Smartphone antenna in flexible PCB

ABSTRACT

A thin, flexible antenna module is provided for use in a smartphone. When the antenna module is assembled in the smartphone, the antenna module provides an MST antenna and an NFC antenna. For this, the antenna module includes a flexible PCB containing coils and further includes a magnetic sheet engaged with flexible PCB. The flexible PCB and the magnetic sheet are attached to each other to form a single body.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND Field

The present disclosure relates to a smartphone antenna module for use ina smartphone and further relates to a smartphone having the antennamodule.

Discussion of Related Technology

Recently, smartphones include a circuit and an antenna for enabling nearfield RF communication (NFC). Also, some smartphones include otherwireless communication circuits and antennas for use in transactions andpayments in stores and restaurants with smartphones. For example, acircuit and an antenna for magnetic secure transmission (MST) areapplied to some smartphones. However, wireless communication circuitsand components for providing various kinds of wireless communications(e.g., LTE communication, Wi-Fi communication and Bluetoothcommunication) are already housed in smartphones, and various antennasare also mounted in smartphones. In addition, smartphones also havecomponents that may affect the wireless communication, such as abattery. Accordingly, spaces for installing an NFC antenna or MSTantenna are limited. This requires additional efforts for designingantennas' structures and layout of components in smartphones.

The foregoing discussion in this section is to provide generalbackground information and does not constitute an admission of priorart.

SUMMARY

In one aspect of the invention provides a smartphone antenna module,which may comprise:

-   -   a flexible PCB comprising a sheet-like body with a first major        surface and a second major surface facing away from the first        major surface;    -   the flexible PCB further comprising a first hole and a second        hole formed through the sheet-like body, wherein the flexible        PCB comprises a first PCB section, the first hole, a second PCB        section, the second hole, and a third PCB section consecutively        arranged along an axis such that the axis passes the first PCB        section, the first hole, the second PCB section, the second        hole, and the third PCB section;    -   the flexible PCB further comprising a first coil, a second coil        and a third coil formed in the sheet-like body between the first        and second major surfaces,    -   the first coil surrounding the first hole and comprising a first        coil segment located in the first PCB section and a second coil        segment located in the second PCB section;    -   the second coil surrounding the second hole and comprising a        second coil segment located in the second PCB section and a        third coil segment located in the third PCB section;    -   a magnetic sheet comprising a first sheet portion, a second        sheet portion and a third sheet portion, the second sheet        portion interposed between the first and third sheet portions,    -   wherein the magnetic sheet engaged with the flexible PCB through        the first and second holes such that:        -   the first sheet portion is located on the side of the first            major surface and overlaps the first coil segment of the            first coil, in which at least one line of the first coil            segment of the first coil overlaps the first sheet portion,        -   the second sheet portion interposed between the first and            third sheet portions is located on the side of the second            major surface and overlaps both the second coil segment of            the first coil and the second coil segment of the second            coil, in which each line of the second coil segment of the            first coil overlaps the second sheet portion and each line            of the second coil segment of the second coil overlaps the            second sheet portion, and        -   the third sheet portion is located on the side of the first            major surface and overlaps the third coil segment of the            second coil, in which each line of the third coil segment of            the second coil overlaps the third sheet portion.

In the foregoing smartphone antenna module, the third coil may surroundboth the first and second coils, wherein the third coil comprises afirst coil segment located in the first PCB section and a third coilsegment in the third PCB section, wherein the first coil segment of thethird coil does not have a line overlapping the first sheet portion,wherein the third sheet portion overlaps the third coil segment of thethird coil, in which each line of the third coil segment of the thirdcoil overlaps the third sheet portion. In the foregoing antenna module,the third coil may surround the first coil, but does not surround thethird coil, wherein the third coil comprises a first coil segmentlocated in the first PCB section and a second coil segment in the secondPCB section, wherein the first sheet portion overlaps the first coilsegment of the third coil, in which at least one line of the first coilsegment of the third coil overlaps the first sheet portion, wherein thesecond sheet portion overlaps the second coil segment of the third coil,in which each line of the second coil segment of the third coil overlapsthe third sheet portion.

Still in the foregoing smartphone antenna module, the magnetic sheetdoes not include a portion extending from the first sheet portion beyondan edge of the flexible PCB that overlaps the first PCB section. Eachline of the first coil segment of the first coil may overlap the firstsheet portion. The magnetic sheet may include a portion extending fromthe third sheet portion beyond an edge of the flexible PCB that overlapswith the third PCB section. The magnetic sheet may continuously extendfrom the first sheet portion to the third sheet portion via the secondsheet portion without an air gap between the first sheet portion and thesecond sheet portion and without air gap between the second sheetportion and the third sheet portion.

Yet in foregoing smartphone antenna module, the first coil may comprisetwo non-overlapping coil segments that do not overlap the magnetic sheetat all, wherein the first coil segment, one of the two non-overlappingcoil segments, the second coil segment, the other non-overlapping coilsegment of the first coil are arranged in order surrounding the firsthole. The second coil may comprise two non-overlapping coil segmentsthat do not overlap the magnetic sheet at all, wherein the second coilsegment, one of the two non-overlapping coil segments, the third coilsegment, the other non-overlapping coil segment of the second coil arearranged in order surrounding the second hole.

Further in the foregoing smartphone antenna module, the first coil andthe second coil may be electrically connected to each other in theflexible PCB to form a combined coil antenna having two end terminals,wherein the flexible PCB further comprises a PCB connector forelectrically connecting the first and second coils to a counterpartconnector of a smartphone, wherein the PCB connector is electricallyconnected to the two end terminals. The first and second coils areconnected in series to each other such that when current flows from oneof the two end terminals toward the other end terminal through the firstand second coils, the current flows in the first coil in a firstrotational direction around the first hole and further flows in thesecond coil in a second rotational direction around the second hole whenviewed in a viewing direction perpendicular to the first major surface,in which the second rotational direction is opposite to the firstrotational direction. The first and second coils are connected to eachother in series such that when current flows from one of the two endterminals toward the other end terminal through the first and secondcoils, the current flows in lines of the second coil segment of thefirst coil in a linear direction and the current flows in lines of thesecond coil segment of the second coil in the same linear direction. Thethird coil surrounds the first coil and the second coil, wherein theflexible PCB further may comprise connection lines interconnecting thetwo end terminals of the combined coil antenna and the PCB connector,wherein one of the connection lines crosses over the third coil whenviewed in a viewing direction perpendicular to the first major surface.The first coil and the second coil may be electrically connected to eachother in series.

Still further in the foregoing smartphone antenna module, wherein theflexible PCB may comprise a first layer and a second layer stacked overeach other, wherein the first layer comprises the first and secondcoils, and the second layer comprises a fourth coil that surrounds thefirst hole, wherein the fourth coil comprises a first coil segmentlocated in the first PCB section and a second coil segment located inthe second PCB section, wherein the first sheet portion overlaps thefirst coil segment of the fourth coil, in which at least one line of thefirst coil segment of the fourth coil overlaps the first sheet portion,wherein the second sheet portion overlaps the second coil segment of thefourth coil, in which each line of the second coil segment of the fourthcoil overlaps the second sheet portion. The first, second and fourthcoils may be electrically connected to one another in series in theflexible PCB to form a combined coil antenna having two end terminals,wherein the flexible PCB further comprises a PCB connector forelectrically connecting the first, second and fourth coils to acounterpart connector of a smartphone, wherein the PCB connector iselectrically connected to the two terminals. The first, second andfourth coils are connected in series such that when current flows fromone of the two end terminals toward the other end terminal through thefirst, second and fourth coils, the current flows in the first andfourth coils in a first rotational direction around the first hole andfurther flows in the third coil in a second rotational direction aroundthe second hole when viewed in a direction perpendicular to the firstmajor surface, wherein the first rotational direction is opposite to thesecond rotational direction. The first, second and fourth coils areconnected in series such that when current flows from one of the two endterminals toward the other end terminal through the first, second andfourth coils, the current flows in lines of the second coil segment ofthe first coil in a linear direction, the current flows in lines of thesecond coil segment of the second coil in the same linear direction, andthe current flows in lines of the second coil segment of the fourth coilin the same linear direction.

Still further in the smartphone antenna module, the third coil maysurround the first coil, but does not surround the third coil, whereinthe flexible PCB further may comprise a fifth coil that surrounds thesecond coil, wherein the first and second coils are connected to eachother for providing a combined coil antenna and the third and fifthcoils are connected to each other in the flexible PCB for providinganother combined coil antenna.

Another aspect of the invention provides a smartphone, which maycomprise: a display module comprising a display surface; one of theforegoing smartphone antenna modules; and a rear wall facing away fromthe display surface and made of a non-magnetic material, wherein themagnetic sheet is arranged generally parallel to the rear wall.

In the foregoing smartphone, at least part of the first sheet portionand at least part of the third sheet portion may be interposed betweenthe rear wall and the first PCB section while at least part of thesecond PCB section is interposed between the rear wall and the secondsheet portion. The first and second coils may be electrically connectedto each other in the flexible PCB and connected to a first smartphonecircuit for magnetic secure transmission (MST) using a frequency rangeof 85-100 KHz, wherein the second coil is connected to a secondsmartphone circuit for near field communication (NFC) using 13.56 MHz.

Still another aspect of the invention provides a smartphone antennamodule which may comprise:

-   -   a magnetic sheet comprising a first magnetic sheet portion, a        second magnetic sheet portion and a third magnetic sheet portion        interposed between the first and second magnetic sheet portions;    -   a flexible PCB comprising a first coil antenna (e.g., coil A)        and a second coil antenna (e.g., coil B); and    -   a through hole formed through the flexible PCB such that the        flexible PCB comprises a first PCB section and a second PCB        section located on an opposite side of the first PCB section        across the through hole,    -   wherein, when viewed in a thickness direction of the flexible        PCB, the first coil antenna surrounds the through hole, and the        second coil antenna surrounds the first coil antenna,    -   wherein no electrical connection is formed between the first        coil antenna and the second antenna coil within the flexible        PCB,    -   wherein the flexible PCB and the magnetic sheet are integrated        in a single, flexible body, in which the flexible PCB and the        magnetic sheet are arranged relative to each other such that: at        least part of the third magnetic sheet portion passes the        through hole, the first magnetic sheet portion is placed over        the first PCB section and overlaps a first coil portion of the        first coil antenna formed in the first PCB section of the        flexible PCB, and the second magnetic sheet portion is placed        under the second PCB section and overlaps a second coil portion        of the first coil antenna formed in second PCB section of the        flexible PCB.

In the foregoing antenna module, the first magnetic sheet portion placedover the first PCB section further may overlap a first coil portion ofthe second coil antenna that are formed in the first PCB section. Thefirst magnetic sheet portion placed over the first PCB section mayextend in a direction away from the second magnetic sheet portion beyondthe first coil portion of the second coil antenna. The first magneticsheet portion placed over the first PCB section may extend in adirection away from the second magnetic sheet portion beyond an edge ofthe flexible PCB that overlaps with the first PCB section.

Still in the foregoing antenna module, the first coil antenna maycomprise a third portion that does not overlap the magnetic sheet atall. The first coil antenna may comprise a fourth portion that does notoverlap the magnetic sheet at all, wherein the first, third, second andfourth portions of the first coil antenna are arranged in ordersurrounding the through hole. The second coil antenna may comprise athird portion and fourth portion that do not overlap the magnetic sheetat all, wherein the first, third, second and fourth portions of thesecond coil antenna are arranged in order surrounding the through hole.

Yet in the foregoing antenna module, the second magnetic sheet portionplaced under the second PCB section further may overlap a second coilportion of the second coil antenna that are formed in the second PCBsection. The first magnetic sheet portion placed over the first PCBsection may further overlap a first coil portion of the second coilantenna that are formed in the first PCB section. The first magneticsheet portion may have a first width for passing through the throughhole without bending thereof whereas the second magnetic sheet portionhas a second width for not passing through the through hole withoutbending thereof. The through hole may have a maximum linear length of anopening thereof, wherein the first magnetic sheet portion has a firstwidth smaller than the maximum linear length whereas the second magneticsheet portion has a second width larger than the maximum linear length.

Further in the foregoing antenna module, the through hole may have amaximum linear length of an opening thereof, wherein the first magneticsheet portion has a first width larger than the maximum linear lengthwhereas the second magnetic sheet portion has a second width larger thanthe maximum linear length. The through hole may have a maximum linearlength of an opening thereof, wherein the first magnetic sheet portionhas a first width smaller than the maximum linear length whereas thesecond magnetic sheet portion has a second width smaller than themaximum linear length.

Still further in the foregoing antenna module, the first coil antennamay comprise a first inner terminal and a first outer terminal, whereinthe flexible PCB may further comprise a PCB connector for electricallyconnecting the first coil antenna to a first counterpart connector of asmartphone, wherein the PCB connector is electrically connected to thefirst inner terminal and the first outer terminal. The flexible PCB mayfurther comprise a connection line interconnecting the first innerterminal and the PCB connector, wherein the connection line crosses overthe first coil antenna and the second coil antenna. The second coilantenna comprises a second inner terminal and a second outer terminal,wherein the PCB connector is also for electrically connecting the secondcoil antenna to a second counterpart connector of the smartphone,wherein the PCB connector is also electrically connected to the secondinner terminal and the second outer terminal. The smartphone antennamodule may further comprise a third coil antenna that is not part of theflexible PCB.

Yet another aspect of the invention provides a smartphone, which maycomprise: a display module comprising a display surface; the foregoingsmartphone antenna module; and a rear wall facing away from the displaysurface and made of a non-magnetic material, wherein the magnetic sheetis arranged generally parallel to the rear wall.

In the foregoing smartphone, at least part of the first magnetic sheetportion may be interposed between the rear wall and the first PCBsection whereas at least part of the second PCB section is interposedbetween the rear wall and the second magnetic sheet portion. The firstcoil antenna may be connected to a first smartphone circuit for magneticsecure transmission (MST) using a frequency range of 85-100 KHz, whereinthe second coil antenna is connected to a second smartphone circuit fornear field communication (NFC) using 13.56 MHz. The antenna module mayfurther comprise a third coil antenna that is not part of the flexiblePCB.

Still another aspect of the invention provides a smartphone antennamodule, which may comprise:

-   -   a flexible PCB comprising a first coil antenna and a second coil        antenna that are not electrically connected with each other        within the flexible PCB;    -   a through hole formed through the flexible PCB such that the        flexible PCB comprises a first PCB section and a second PCB        section located on an opposite side of the first PCB section        across the through hole, wherein when viewed in a thickness        direction of the flexible PCB, the first coil antenna surrounds        the through hole and the second coil antenna surrounds the first        coil antenna;    -   a first magnetic sheet placed under or over the first PCB        section and overlapping a first coil portion of the first coil        antenna that are formed in the first PCB section, the first        magnetic sheet comprising a first edge;    -   a second magnetic sheet placed under or over the second PCB        section and overlapping a second coil portion of the first coil        antenna that are formed in the second PCB section located on an        opposite side of the first PCB section across the through hole,        the second magnetic sheet comprising a second edge,    -   wherein the first magnetic sheet and the second magnetic sheet        are arranged such that the first edge of the first magnetic        sheet overlaps the second magnetic sheet or that the first edge        and the second edge are in proximity with each other with a gap        therebetween,    -   wherein the flexible PCB, the first magnetic sheet and the        second magnetic sheet are integrated in a single, flexible body.

In the foregoing antenna module, the gap may be greater than 0 mm andless than a distance in a range of 0.1 mm to 3 mm.

A further aspect of the invention provides a smartphone, which maycomprise: a display module comprising a display surface; the foregoingsmartphone antenna module; and a rear wall facing away from the displaysurface and made of a non-magnetic material, wherein the magnetic sheetis arranged generally parallel to the rear wall.

In the foregoing smartphone, the first coil antenna is connected to afirst smartphone circuit for magnetic secure transmission (MST) using afrequency range of 85-100 KHz, wherein the second coil antenna isconnected to a second smartphone circuit for near field communication(NFC) using 13.56 MHz.

Still a further aspect of the invention provides a smartphone antennamodule comprising:

-   -   a magnetic sheet comprising a first sheet portion, a second        sheet portion and a third sheet portion, the second sheet        portion interposed between the first and third sheet portions;    -   a flexible PCB comprising a first coil (coil A) and a second        coil (coil C), wherein when viewed in a thickness direction of        the flexible PCB, the first and second coils are arranged side        by side;    -   a first through hole formed through the flexible PCB and        surrounded by the first coil when viewed in the thickness        direction;    -   a second through hole formed through the flexible PCB and        surrounded by the second coil when viewed in the thickness        direction; and    -   the flexible PCB comprises a first PCB section, a second PCB        section and a third PCB section, the second PCB section        interposed between the first and second through holes, wherein        the first and second PCB sections are located opposite to each        other across the first through hole and the second and third PCB        sections are located opposite to each other across the second        through hole such that the second PCB section is located between        the first and third PCB sections,    -   wherein the flexible PCB and the magnetic sheet are integrated        in a single, flexible body, in which the flexible PCB and the        magnetic sheet are arranged relative to each other such that:        -   the first sheet portion is placed over the first PCB section            and overlaps a first coil portion of the first coil formed            in the first PCB section of the flexible PCB,        -   the second sheet portion is placed under the second PCB            section, overlaps a second coil portion of the first coil            formed in the second PCB section and further overlaps a            first coil portion of the second coil formed in the second            PCB section,        -   the magnetic sheet comprises a first intermediate sheet            portion connecting the first and second sheet portions and            passing through the first through hole,        -   the third sheet portion is placed over the third PCB section            and overlaps a second coil portion of the second coil formed            in the third PCB section of the flexible PCB, and        -   the magnetic sheet comprises a second intermediate portion            connecting the second and third sheet portions and passing            through the second through hole.

One aspect of the invention provides a smartphone antenna module whichmay comprise the following:

-   -   a flexible PCB comprising a sheet-like body with a first major        surface and a second major surface facing away from the first        major surface;    -   the flexible PCB further comprising a through-hole formed        through the sheet-like body, wherein the flexible PCB comprises        a first PCB section, the through-hole and a second PCB section        arranged along an axis such that the axis passes the first PCB        section, the through-hole and the second PCB section in order;    -   the flexible PCB further comprising a first coil, a second coil        and a third coil formed in the sheet-like body between the first        and second major surfaces;    -   the first coil comprising a first coil segment located in the        first PCB section and a second coil segment located in the        second PCB section;    -   the second coil comprising a first coil segment located in the        first PCB section and a second coil segment located in the        second PCB section;    -   the third coil located in the second PCB section;    -   the second coil surrounding the first coil, the through hole and        at least a portion of the third coil; and    -   a magnetic sheet comprising a head portion, a base portion and a        neck portion interposed between and interconnecting the head and        base portions,    -   wherein no electric connection is formed between any two coils        of the first, second and third coils in the flexible PCB,    -   wherein the magnetic sheet is engaged with the flexible PCB:        -   such that the head portion is located on the side of the            first major surface and overlaps the first coil segment of            the first coil, in which the head portion overlaps at least            one line of the first coil segment of the first coil while            the head portion does not overlap any line of the first coil            segment of the second coil,        -   such that the neck portion passes through and overlaps the            through-hole; and        -   such that the base portion is located on the side of the            second major surface and overlaps the third coil, the second            coil segment of the first coil and the second coil segment            of the second coil, in which the base portion overlaps each            line of the second coil segment of the first coil, each line            of the second coil segment of the second coil and each line            of the third coil and the entire portion of the third coil,    -   wherein the magnetic sheet overlaps each line of the second coil        segment of the second coil whereas the magnetic sheet does not        overlap any line of the first coil segment of the second coil.

In the foregoing smartphone antenna module, the third coil may belocated between the second segment of the first coil and the secondsegment of the second coil, wherein the second coil surrounds the entirethird coil. The second coil segment of the second coil may comprise aplurality of lines generally perpendicular to the axis, wherein theplurality of lines comprises a first line and a second line locatedinside the first line, wherein the second line crosses the third coilwhen viewed in a thickness direction of the flexible PCB whereas a firstline does not cross the third coil such that the entire portion of thethird coil is located between the second line and the second segment ofthe first coil. The second coil may comprise two or more turns thatcomprises a first turn and a second turn, wherein the first turnsurrounds entire portion of the third coil whereas the second turnsurrounds a portion of the third coil and comprises a line crossing thethird coil when viewed in a thickness direction of the flexible PCB.

Still in the foregoing module, each of the first, second and third coilsmay comprise a printed wire that is coiled to form one or more turns ina spiral shape when viewed in a thickness direction of the flexible PCB.The printed wire may comprise a first wire segment and a second wiresegment formed in different layers of the flexible PCB and connectedthrough a connection via. Each line of the second coil segment of thefirst coil may comprise a linear extension along a directionperpendicular to the axis, wherein the base portion overlaps the entireportion of the linear extension of the first coil along the direction,wherein each line of the second coil segment of the second coilcomprises a linear extension along a direction perpendicular to theaxis, wherein the base portion overlaps the entire portion of the linearextension of the second coil along the direction.

Yet in the foregoing module, each line of the first coil segment of thefirst coil may comprise a linear extension along a directionperpendicular to the axis, wherein the head portion overlaps the atleast one line of the first coil segment such that only a centralportion of the linear extension of the at least one line overlaps thehead portion with non-overlapped portions at both ends of the centralportion. The magnetic sheet may include a portion extending from thebase portion beyond an edge of the flexible PCB that overlaps with thesecond PCB section. The first coil antenna may comprise third and fourthcoil segments that do not overlap the magnetic sheet at all, wherein thefirst, third, second and fourth coil segments of the first coil arearranged in order surrounding the through hole. The second coil antennamay comprise third and fourth coil segments that do not overlap themagnetic sheet at all, wherein the first, third, second and fourth coilsegments of the second coil are arranged in order surrounding thethrough hole. The head portion may have a first width for passingthrough the through hole without bending thereof whereas the baseportion has a second width for not passing through the through holewithout bending thereof. The base portion may have a width greater thanthat of the neck portion, and the head portion has a width equal to orsmaller than that of the neck portion. The neck portion may have a widthsmaller than those of the head portion and the base portion.

Further in the foregoing module, the through-hole may have a maximumlinear length of an opening thereof, wherein the head portion has afirst width smaller than the maximum linear length whereas the baseportion has a second width larger than the maximum linear length. Eachof the first, second and third coils may comprise an inner terminal andan outer terminal, wherein the flexible PCB further comprises a PCBconnector for electrically connecting each coil to a counterpartconnector of a smartphone, wherein the PCB connector is electricallyconnected to the inner terminal and the outer terminal. The flexible PCBfurther may comprise a connection line interconnecting the innerterminal of the first coil antenna and the PCB connector, wherein theconnection line crosses over the first coil antenna and the second coilantenna without electric connection with the second coil in the flexiblePCB. The flexible PCB may further comprise a fourth coil formed in alayer different from that of the first coil, wherein the fourth coilsurrounds the through-hole, wherein the fourth coil is coiled in arotational direction opposite that of the first coil when viewed in athickness direction of the flexible PCB, wherein the first coil and thefourth coil are electrically connected in series. The flexible PCB mayfurther comprise a fourth coil formed in a layer different from that ofthe first coil, wherein the fourth coil surrounds the through-hole,wherein the first and fourth coils are coiled in the same rotationaldirection when viewed in a thickness direction of the flexible PCB,wherein the first coil and the fourth coil are electrically connected inparallel. The flexible PCB may further comprises a fourth coil formed ina layer different from that of the first coil, wherein the fourth coilsurrounds the through-hole, wherein the fourth coil comprising a firstcoil segment located in the first PCB section and a second coil segmentlocated in the second PCB section such that the first coil segment ofthe fourth coil overlaps the head portion while the second coil segmentof the fourth coil overlaps the base portion.

Another aspect of the invention provides a smartphone which may comprisea display module comprising a display surface; the foregoing smartphoneantenna module; and a rear wall facing away from the display surface andmade of a non-magnetic material, wherein the magnetic sheet is arrangedgenerally parallel to the rear wall. In the foregoing smartphone, atleast part of the base portion may be interposed between the rear walland the second PCB section whereas at least part of the first PCBsection is interposed between the rear wall and the head portion. Thefirst coil antenna may be connected to a first smartphone circuit andconfigured for magnetic secure transmission (MST) using a frequencyrange of 85-100 KHz, wherein the second coil antenna is connected to asecond smartphone circuit and configured for near field communication(NFC) using 13.56 MHz, wherein the third coil antenna is connected to athird smartphone circuit and configured for wireless charging of thesmartphone.

Still another aspect of the invention provides a smartphone antennamodule which may comprise:

-   -   a magnetic sheet comprising a first magnetic sheet portion, a        second magnetic sheet portion and a third magnetic sheet portion        interposed between the first and second magnetic sheet portions,    -   a flexible PCB in form of a sheet having a thickness, the        flexible PCB comprising a first coil antenna and a second coil        antenna; and    -   a through hole formed through the thickness of the sheet of the        flexible PCB such that the flexible PCB comprises a first PCB        section and a second PCB section located on an opposite side of        the first PCB section across the through hole,    -   wherein, when viewed in a thickness direction of the flexible        PCB, the first coil antenna comprises two or more turns turning        around the through hole, and the second coil antenna comprises        two or more turns turning around the first coil antenna and the        through hole,    -   wherein no electrical connection is formed between the first        coil antenna and the second coil antenna within the flexible        PCB,    -   wherein the flexible PCB and the magnetic sheet are integrated        in a single, flexible body, in which the flexible PCB and the        magnetic sheet are arranged relative to each other such that:        -   at least part of the third magnetic sheet portion passes the            through hole,        -   the first magnetic sheet portion is placed over the first            PCB section and overlaps, when viewed in the thickness            direction, a first coil portion of the first coil antenna            formed in the first PCB section of the flexible PCB while            not overlapping, when viewed in the thickness direction, a            second coil portion of the first coil antenna formed in the            second PCB section that is placed across the through hole,        -   the second magnetic sheet portion is placed under the second            PCB section and overlaps, when viewed in the thickness            direction, the second coil portion of the first coil antenna            formed in the second PCB section of the flexible PCB while            not overlapping, when viewed in the thickness direction, the            first coil portion of the first coil antenna formed in the            first PCB section placed across the through hole, and        -   the second magnetic sheet portion further overlaps, when            viewed in the thickness direction, a second coil portion of            the second coil antenna formed in the second PCB section            while not overlapping, when viewed in the thickness            direction, a first coil portion of the second coil antenna            formed in the first PCB section that is placed across the            through hole.

Yet another aspect of the invention provides a smartphone antenna modulewhich may comprise:

-   -   a magnetic sheet comprising a first magnetic sheet portion, a        second magnetic sheet portion and a third magnetic sheet portion        interposed between the first and second magnetic sheet portions,    -   a flexible PCB in form of a sheet having a thickness, the        flexible PCB comprising a first coil antenna, a second coil        antenna and a third coil antenna; and    -   a through hole formed through the thickness of the sheet of the        flexible PCB such that the flexible PCB comprises a first PCB        section and a second PCB section located on an opposite side of        the first PCB section across the through hole,    -   wherein, when viewed in a thickness direction of the flexible        PCB, the first coil antenna comprises two or more turns turning        around the through hole, and the second coil antenna comprises        two or more turns turning around the first coil antenna, the        third coil antenna and the through hole,    -   wherein no electrical connection is formed between the first        coil antenna and the second coil antenna within the flexible        PCB, no electrical connection is formed between the third coil        and the first coil antenna within the flexible PCB, and no        electrical connection is formed between the third coil and the        second coil antenna within the flexible PCB,    -   wherein the flexible PCB and the magnetic sheet are integrated        in a single, flexible body, in which the flexible PCB and the        magnetic sheet are arranged relative to each other such that:        -   at least part of the third magnetic sheet portion passes the            through hole,        -   the first magnetic sheet portion is placed over the first            PCB section and overlaps, when viewed in the thickness            direction, a first coil portion of the first coil antenna            formed in the first PCB section of the flexible PCB while            not overlapping, when viewed in the thickness direction, a            second coil portion of the first coil antenna formed in the            second PCB section that is placed across the through hole,        -   the second magnetic sheet portion is placed under the second            PCB section and overlaps, when viewed in the thickness            direction, the second coil portion of the first coil antenna            formed in the second PCB section of the flexible PCB while            not overlapping, when viewed in the thickness direction, the            first coil portion of the first coil antenna formed in the            first PCB section that is placed across the through hole,            and        -   the second magnetic sheet portion further overlaps, when            viewed in the thickness direction, a second coil portion of            the second coil antenna formed in the second PCB section            while not overlapping, when viewed in the thickness            direction, a first coil portion of the second coil antenna            formed in the first PCB section that is placed across the            through hole.

A further aspect of the invention provides a smartphone antenna modulethat may comprise:

-   -   a flexible PCB comprising a sheet-like body with a first major        surface and a second major surface facing away from the first        major surface;    -   the flexible PCB further comprising a first hole and a second        hole formed through the sheet-like body, wherein the flexible        PCB comprises a first PCB section, the first hole, a second PCB        section, the second hole, and a third PCB section arranged along        an axis such that the axis passes the first PCB section, the        first hole, the second PCB section, the second hole, and the        third PCB section in order;    -   the flexible PCB further comprising a first coil, a second coil        and a third coil formed in the sheet-like body between the first        and second major surfaces;    -   the first coil surrounding the first hole and comprising a first        coil segment located in the first PCB section and a second coil        segment located in the second PCB section;    -   the second coil surrounding the second hole and comprising a        second coil segment located in the second PCB section and a        third coil segment located in the third PCB section;    -   the third coil surrounding all of the first coil, the first        hole, the second coil and the second hole and comprising a first        coil segment located in the first PCB section and a third coil        segment located in the third PCB section; and    -   a magnetic sheet comprising a first sheet portion, a second        sheet portion and a third sheet portion, the second sheet        portion interposed between the first and third sheet portions,    -   wherein the magnetic sheet engaged with the flexible PCB through        the first and second holes:        -   such that the first sheet portion is located on the side of            the first major surface and overlaps the first coil segment            of the first coil, in which the first sheet portion overlaps            at least one line of the first coil segment of the first            coil while the first sheet portion does not overlap any line            of the first coil segment of the third coil,        -   such that the second sheet portion interposed between the            first and third sheet portions is located on the side of the            second major surface and overlaps both the second coil            segment of the first coil and the second coil segment of the            second coil, in which the second sheet portion overlaps each            line of the second coil segment of the first coil and each            line of the second coil segment of the second coil, and        -   such that the third sheet portion is located on the side of            the first major surface and overlaps the third coil segment            of the second coil and the third coil segment of the third            coil, in which the third sheet portion overlaps each line of            the third coil segment of the second coil and each line of            the third coil segment of the third coil,    -   wherein the magnetic sheet overlaps each line of the third coil        segment of the third coil whereas the magnetic sheet does not        overlap any line of the first coil segment of the third coil.

Still a further aspect of the invention provides a smartphone antennamodule that may comprise:

-   -   a flexible PCB comprising a sheet-like body with a first major        surface and a second major surface facing away from the first        major surface;    -   the flexible PCB further comprising a first hole and a second        hole formed through the sheet-like body, wherein the flexible        PCB comprises a first PCB section, the first hole, a second PCB        section, the second hole, and a third PCB section arranged along        an axis such that the axis passes the first PCB section, the        first hole, the second PCB section, the second hole, and the        third PCB section in order;    -   the flexible PCB further comprising a first coil, a second coil,        a third coil and a fourth coil formed in the sheet-like body        between the first and second major surfaces, wherein the sheet        like body comprises a first layer and a second layer stacked        over the first layer, wherein the first and second coils are        formed in the first layer while the fourth coil is formed in the        second layer;    -   the first coil surrounding the first hole and comprising a first        coil segment located in the first PCB section and a second coil        segment located in the second PCB section;    -   the fourth coil surrounding the first hole and comprising a        first coil segment located in the first PCB section and a second        coil segment located in the second PCB section;    -   the second coil surrounding the second hole and comprising a        second coil segment located in the second PCB section and a        third coil segment located in the third PCB section;    -   the third coil surrounding all of the first coil, the fourth        coil, the first hole, the second coil and the second hole and        comprising a first coil segment located in the first PCB section        and a third coil segment located in the third PCB section; and    -   a magnetic sheet comprising a first sheet portion, a second        sheet portion and a third sheet portion, the second sheet        portion interposed between the first and third sheet portions,    -   wherein the magnetic sheet engaged with the flexible PCB through        the first and second holes:        -   such that the first sheet portion is located on the side of            the first major surface and overlaps the first coil segment            of the first coil and the first coil segment of the fourth            coil, in which the first sheet portion overlaps at least one            line of the first coil segment of the first coil and at            least one line of the first coil segment of the fourth coil            while the first sheet portion does not overlap any line of            the first coil segment of the third coil,        -   such that the second sheet portion interposed between the            first and third sheet portions is located on the side of the            second major surface and overlaps the second coil segment of            the first coil, the second coil segment of the second coil            and the second coil segment of the fourth coil, in which the            second sheet portion overlaps each line of the second coil            segment of the first coil, each line of the second coil            segment of the second coil and each line of the second coil            segment of the fourth coil, and        -   such that the third sheet portion is located on the side of            the first major surface and overlaps the third coil segment            of the second coil and the third coil segment of the third            coil, in which the third sheet portion overlaps each line of            the third coil segment of the second coil and each line of            the third coil segment of the third coil,    -   wherein the magnetic sheet overlaps each line of the third coil        segment of the third coil whereas the magnetic sheet does not        overlap any line of the first coil segment of the third coil,    -   wherein each of the first, second and fourth coils comprises an        inner terminal and an outer terminal, wherein the first coil is        coiled about the first hole from the inner terminal of the first        coil to the outer terminal of the first coil in a first        rotational direction, the second coil is coiled about the second        hole from the inner terminal of the second coil to the outer        terminal of the second coil in a second rotational direction        that is opposite to the first rotational direction, the fourth        coil is coiled about the first hole from the inner terminal of        the fourth coil and the outer terminal of the fourth coil in the        second rotational direction, and the first, second and fourth        coils are connected to each other to form a serial connection        such that, when current flows through the first, second and        fourth coils, the current flows in the same direction in each        line of the second coil segments of the first, second and fourth        coils.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a smartphone according to embodiments ofthe present invention, showing a front side of the smartphone.

FIG. 2 is a perspective view of the smartphone shown in FIG. 1, showinga backside of the smartphone with an antenna module inside thesmartphone according to an embodiment of the invention.

FIG. 3 is a perspective view of an antenna module according to anembodiment of the invention.

FIG. 4 is a front view of the antenna module shown in FIG. 3.

FIG. 5 is a rear view of the antenna module shown in FIG. 3.

FIG. 6 is a perspective view of a flexible PCB according to anembodiment of the invention.

FIG. 7 is a perspective view of a magnetic sheet according to anembodiment of the invention.

FIG. 8 is a perspective view of an assembly of the flexible PCB of FIG.6 and the magnetic sheet of FIG. 7 according to an embodiment.

FIG. 9 is a rear view of the assembly shown in FIG. 8.

FIG. 10 is a sectional view of a rear cover of a smartphone and anantenna module according to an embodiment of the invention, showinglocational relationship between the rear cover and the antenna module.

FIGS. 11-14 are partial sectional views of a rear cover of a smartphoneand an antenna module, each showing locational relationship between therear cover and the antenna module according to various embodiments ofthe invention.

FIG. 15 is a perspective view of an assembly of a flexible PCB andmultiple magnetic sheet pieces according to another embodiment of theinvention.

FIG. 16 is a perspective view of two overlapping magnetic sheetsaccording to a further embodiment of the invention, in which the twooverlapping magnetic sheets have different sizes and differentmaterials.

FIG. 17 is a sectional view of an assembly of a flexible PCB and the twooverlapping magnetic sheets shown in FIG. 16.

FIGS. 18A and 18B show examples of electrical connection of two coils,in which FIG. 18A shows a series connection and FIG. 18B shows aparallel connection.

FIG. 19 is a perspective view of the antenna module according to anembodiment of the invention.

FIG. 20 is a front view of a flexible PCB of the antenna module shown inFIG. 19, schematically showing a pattern of coils, conductive lines andterminal pads in the flexible PCB.

FIG. 21 is a sectional view of the antenna module shown in FIG. 19, inwhich a rear cover of a smartphone is partially illustrated as well.

FIG. 22 shows front views of bottom and top layers of a flexible PCBaccording to an alternative embodiment of the antenna module shown inFIG. 19, schematically illustrating patterns of coils, conductive linesand terminal pads in the top and bottom layers of the flexible PCB.

FIGS. 23A and 23B show examples of parallel connections between coils inthe bottom layer of the flexible PCB shown in FIG. 22 and conductiveline segments in the top layer.

FIG. 24 is a computer design printout of patterns of coils, conductivelines and terminal pads of the bottom and top layers of the flexiblePCB.

FIG. 25 is a sectional view of the antenna module with the flexible PCBshown in FIG. 22, in which a rear cover of a smartphone is partiallyillustrated as well.

FIG. 26 is a perspective view of an antenna module according to anotherembodiment of the invention.

FIG. 27 is a front view of a flexible PCB of the antenna module shown inFIG. 26, schematically showing a pattern of coils, conductive lines andterminal pads in the flexible PCB.

FIG. 28 is a sectional view of the antenna module with the flexible PCBshown in FIG. 27, in which a rear cover of a smartphone is partiallyillustrated as well.

FIG. 29 shows a front view of a flexible PCB according to an alternativeembodiment of the antenna module shown in FIG. 26, schematicallyillustrating schematically showing a pattern of coils, conductive linesand terminal pads in the flexible PCB.

FIG. 30 is a sectional view of the antenna module with the flexible PCBshown in FIG. 29, in which a rear cover of a smartphone is partiallyillustrated as well.

FIG. 31 is a perspective view of an antenna module according to afurther embodiment of the invention.

FIG. 32 is a perspective view of a smartphone antenna module and showsanother embodiment of the invention.

FIG. 33 is an exploded view of the smartphone antenna module shown inFIG. 32.

FIG. 34 is a sectional view of the smartphone antenna module shown inFIG. 32.

FIG. 35 is a perspective view of a smartphone antenna module and showsyet another embodiment of the invention.

FIG. 36 is another perspective view of the smartphone antenna moduleshown in FIG. 35.

FIG. 37 is a front view of a flexible PCB of the smartphone antennamodule shown in FIG. 35.

FIG. 38 is a front view of a magnetic sheet of the smartphone antennamodule shown in FIG. 35.

FIG. 39 is a sectional view of the smartphone antenna module shown inFIG. 35, showing a state in which the smartphone antenna module isinstalled in a smartphone.

FIG. 40 is a front view of a smartphone antenna module according to afurther embodiment.

FIG. 41 is a rear view of the smartphone antenna module shown in FIG.40.

FIG. 42 is a front view of a top layer of a flexible PCB of thesmartphone antenna module shown in FIG. 40.

FIG. 43 is a front view of a bottom layer of a flexible PCB of thesmartphone antenna module shown in FIG. 40.

FIG. 44 shows connection of lines formed in multiple layers of theflexible PCB.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the invention are now described with reference to theaccompanying drawings. The terminology used in the description presentedherein is not intended to be interpreted in any limited or restrictivemanner, simply because it is being utilized in conjunction with adetailed description of certain specific embodiments of the invention.

Various Components in Smartphone

In embodiments, referring to FIGS. 1 and 2, a smartphone 10 includescomponents which include circuits, a display 12, a battery, a camera 15,communication modules and the like. The components are denselyintegrated in a housing 18 of the smartphone. Recently, for variousreasons, the housing of the smartphone tends to be made of a metal.However, the metal housing may significantly affect operations ofvarious antennas in the smartphone. Even in smartphones usingnon-metallic housing, due to the high degree of compactness, internalcomponents such as a battery may also significantly affect theoperations of the antennas.

NFC Antenna and MST Antenna

In embodiments, a smartphone can include an NFC antenna and an MSTantenna. The NFC antenna and the MST antenna, among the antennas, use aconsiderably low frequency band and handle wireless signals ofconsiderably long wavelengths as compared with other wireless antennas,it is typical that the NFC antenna and the MST antenna have sizesgreater than those of other antennas. Accordingly, the location of theNFC antenna and the MST antenna overlap with the location of the metalhousing, the battery or the like more than those of the other antennas.This requires improvements in the structures of the NFC antenna and theMST antenna and further requires improved layout arranging the NFCantenna and the MST antenna. In embodiments, referring to FIG. 2, aflexible antenna module or apparatus 100 is included in the smartphone.

Flexible Antenna Module

In embodiments, referring to FIGS. 2-5, a flexible antenna module orapparatus 100 is formed in a single, thin, flexible body in which coilantennas for providing an MST antenna and an NFC antenna are integrated.The flexible antenna module includes a flexible PCB 200 with coilantenna (coil A) 204 and coil antenna (coil B) 206 for providing the MSTantenna and the NFC antenna and further includes a magnetic sheet 300which is engaged with the flexible PCB 200. The flexible PCB 200 and themagnetic sheet 300 are integrated with each other to form the single,thin, flexible body. In embodiments, additional protective andinsulating coatings 400 may be coated over surfaces of the single body(see FIG. 5).

Flexible PCB

In embodiments, referring to FIGS. 3-6, 8, and 9, the flexible PCB 200has a rectangular sheet shape with a through hole 202 at its center. Theflexible PCB 300 includes two coil antennas 204, 206 and coatings coatedover the coil antennas to form the sheet shape. Each coil antennaincludes a printed wire coil. The two coil antennas include a first coilantenna 204 which functions as an MST antenna and a second coil antenna206 which functions as an NFC antenna.

First Coil Antenna and Second Coil Antenna

In embodiments, referring to FIGS. 3-6, 8, and 9, the first coil antenna204 surrounds or encircles the through hole 202 and the second coilantenna 206 surrounds encircles the first coil antenna 204 and thethrough hole 202. In embodiments, the first coil 204 may include 6, 7,8, 9, 10, 11 or 12 turns coiled to turn around the through hole 202, butthe invention is not limited thereto. The second coil 306 may include 2,3, 4, 5 or 6 turns coiled to turn around the first coil 204 and thethrough hole 202, but the invention is not limited thereto. The numberof turns of each coil may be modified or adjusted to provide an antennalength for a specific antenna function. In embodiments, the first coilantenna 204 includes turns more than that of the second coil antenna206.

PCB Connector Portion

In embodiments, referring to FIGS. 3-6, 8, and 9, the flexible PCB 200includes a PCB connector portion 208 for connecting the coil antennas204, 206 to a counterpart connection terminal of a smartphone 10. Theconnector portion 208 includes an extension 210 located outside thesecond coil antenna 206 and four connector terminal pads 212 (see FIG.9) formed in an end portion of the extension 210. Each coil antennaincludes an inner terminal and an outer terminal. In an embodiment, thefirst coil antenna 204 includes a first inner terminal located in itsinner portion and a first outer terminal located in its outer portion.Likewise, the second coil antenna 206 includes a second inner terminallocated in its inner portion and a second outer terminal located in itsouter portion. Each of the first and second inner terminals and thefirst and second outer terminals 204 and 206 is connected to one of thefour terminal pads 212 via one or more connector lines.

Location of Connector Portion

In the embodiments illustrated in FIGS. 3-6, 8, and 9, the connectorportion 208 includes the extension 210 extending from an upper edge ofthe flexible PCB. In some embodiments, the extension 210 may extend froma side of the flexible PCB 200 as shown in FIG. 19. Further, in otherembodiments, may extend from a lower edge of the flexible PCB. In thediscussion of embodiments, the terms “upper” and “lower” do not refer totheir absolute location. In some circumstances, for example, an itemlabeled with the term “upper” may be located lower or under an itemlabeled with the term “lower.

Connector Lines

In embodiments, referring to FIGS. 3-6, 8, and 9, the flexible PCB 200includes connector lines interconnecting between four terminal pads 212and the terminals of the coil antennas, respectively. Connector linesinclude printed conductive lines. For example, a connector line 214connects the inner terminal of the first coil antenna and one of theterminal pads 212. The connector line 214 extends from the inner portionof the first coil antenna 204 and the outer portion of the second coilantenna 206 (see FIGS. 6 and 9), while crossing lines of the first andsecond coil antennas 204 and 206 when viewed in a viewing directionalong an arrow A shown in FIG. 6 and while extending over the front sideof the first coil antenna 204 and the rear side of the second coilantenna 206. (Throughout the discussion of embodiments in thespecification, the viewing direction is defined as a thickness directionof the flexible PCB generally perpendicular to a major flat surface ofthe flexible PCB. In some instances, the viewing direction may also bethe same as a thickness direction of the magnetic sheet generallyperpendicular to a major flat surface of the magnetic sheet. In otherinstances, the viewing direction may also be the same as a directiongenerally perpendicular to a major flat surface of the rear cover orrear wall of the smartphone when the antenna module is assembled in thesmartphone.) Another connector line 216 among the connector linesconnects the outer terminal of the first coil antenna 204 and one of theterminal pads 212. In embodiments, the connector lines may be formed ina layer of the flexible PCB that is different from another layer inwhich the first and second coils are formed.

Width and Thickness of Connector Lines

In embodiments, the connector line has a width greater than that of aline in the first coil antenna 204 and has a thickness smaller than thatof the line in the first coil antenna 204. This configuration can reduceor minimize overall thickness of the antenna module when the coilantenna and the connector line are overlaid. The connector line 216extends from the inner portion of the second coil antenna 206 and theouter portion of the first coil antenna 204, while crossing lines of thesecond coil antenna 206 when viewed in the viewing direction and whileextending over the rear side of the second coil antenna 206. In theflexible PCB 200, the connector lines are insulated from the coilantennas 204 and 206 that they are crossing via insulation layers.

No Electrical Connection Between First Coil Antenna and Second CoilAntenna

In embodiments, referring to FIGS. 3-6, 8, and 9, there is no electricconnection between the first coil antenna 204 and the second coilantenna 206 in the antenna module. Specifically, the first coil antenna204 and the second coil antenna 206 are spaced apart from each otherwhile the second coil antenna 206 surrounds or encircles the first coilantenna 204. Further, each of the connector lines is also spaced fromother connector lines. One or more insulation layers are interposedbetween the first or second coil antenna and the connector linescrossing the first or second coil antenna. Also, each of the fourconnector terminal pads is apart from other connector terminal pads.

Magnetic Sheet

In embodiments, referring to FIGS. 3-5, and 7-9, the magnetic sheet 300includes a generally rectangular base portion 302 and a head portion 304extending from an edge 306 of the base portion 302. The head portion iscontoured and sized to pass through the through hole 202 and has a widthsmaller than that of the base portion. In embodiments discussed aboveand below, the magnetic sheet may function as a magnetic core when themagnetic sheet passes through a through hole that a coil surrounds orthe magnetic sheet is placed adjacent a coil.

Material of Magnetic Sheet

In embodiments, the magnetic sheet 300 contains magnetic material whichis referred to as soft magnetic material or ferromagnetic materialhaving a high magnetic permeability and a low coercive force. Forexample, ferrite or ferromagnetic metal or alloy can be used. Inembodiments, the magnetic sheet is entirely made of the magneticmaterial. In other embodiments, the magnetic material powder orparticles are dispersed in a plastic resin matrix of flexible sheetshape.

Ferrite Magnetic Sheet

In embodiments, the magnetic sheet 300 includes ferrite material. In oneembodiment, ferrite magnetic material powder or particles are preparedand sintered to make the ferrite magnetic material sheet.

Nanocrystal Magnetic Sheet

In embodiments, the magnetic sheet 300 includes a laminate of pluralnanocrystal sheets or layer. In one embodiment, each nanocrystal sheetor layer contains an alloy including or essentially consisting of iron(Fe), silicon (Si) and boron (B). Additionally, a small amount of copper(Cu), molybdenum (Mo), niobium (Nb) and nickel (Ni) may be added to thealloy. Typically, each nanocrystal sheet or layer is made thin, andthus, plural nanocrystal sheets (e.g., four or more nanocrystal magneticsheets) are laminated to form the magnetic sheet 300.

Assembled State of Flexible PCB and Magnetic Sheet

In embodiments, referring to FIGS. 6-9, the flexible PCB 200 and themagnetic sheet 300 may be assembled as shown in the drawings. Whenassembled, the head portion 304 of the magnetic sheet 300 passes throughthe through hole 202. The head portion 304 has a first sheet portion 320placed over a first PCB section 220 of the flexible PCB while the baseportion 302 has a second sheet portion 322 placed under a second PCBsection 222 of the flexible PCB. The second PCB section 222 is locatedon an opposite side of the first PCB section 220 across the through hole202.

Coils and Magnetic Sheet

As a result, in embodiments, the first sheet portion 320 overlaps coilportions of the first coil antenna 204 which are located in the firstPCB section 220. Further, the first sheet portion 320 further overlapscoil portions of the second coil antenna 206 which are located in thefirst PCB section 220. Similarly, the second sheet portion 322 overlapscoil portions of the first coil antenna 204 which are located in thesecond PCB section 222. Further, the second sheet portion 322 furtheroverlaps coil portions of the second coil antenna 206 which are locatedin the second PCB section. In other embodiments, the first sheet portiondoes not overlap the coil portions of the second coil antenna 206 whichare located in the first PCB section 220 while the first sheet portion320 further overlaps coil portions of the second coil antenna 206 whichare located in the first PCB section 220.

Through Hole and Magnetic Sheet

In embodiments, referring to FIG. 8, the magnetic sheet 300 furtherincludes an intermediate sheet portion 312 overlapping the through hole202. The intermediate sheet portion 312 interconnects the first sheetportion 320 and the second sheet portion. In one embodiment, theintermediate sheet portion 312 may be a portion of the head portion 304.In another embodiment, the intermediate sheet portion 312 may be aportion of the base portion 302. In other embodiments, the intermediatesheet portion 321 may include both a portion of the head portion 304 anda portion of the base portion 302.

Assembling Flexible PCB and Magnetic Sheet

In embodiments, referring to FIGS. 6-9, when assembling, the headportion 304 is inserted through the through hole 202 and passes thethrough hole 202 until the edge 306 contacts the flexible PCB. Then, thebase portion 302 is attached to the second PCB section 222 by using, forexample, an adhesive. In other embodiments, the head portion 304 isattached to the first PCB section 220.

Sizes of Portions of Flexible PCB and the Portions of Magnetic Sheet

In embodiments, referring to FIGS. 6, 7 and 8, the head portion 304 (thefirst sheet portion 320) has a width W_(H) smaller than that W_(T) ofthe through hole 202 such that the head portion 304 passes through thethrough hole without bending the magnetic sheet 300. Further, the baseportion 302 (the second sheet portion 322) has a width W_(B) greaterthan that W_(T) of the through hole 202 such that the head portion 304cannot pass through the through hole without bending the magnetic sheet300. Additionally, the base portion 302 (the second sheet portion 322)has a width W_(B) greater than that W_(C2) of the second coil antenna206. However, the invention is not limited thereto. In anotherembodiment, the base portion 302 (the second sheet portion 322) has awidth W_(B) smaller than that W_(T) of the through hole 202. In afurther embodiment, the head portion 304 (the first sheet portion 320)has a width W_(H) greater than that W_(T) of the through hole 202 suchthat the head portion 304 passes through the through hole with bendingthe magnetic sheet 300. In other embodiments, the head portion 304 (thefirst sheet portion 320) has a width W_(H) substantially the same asthat W_(B) of the base portion 302 (the second sheet portion 322).

Single Body of Flexible Antenna Module

Over surfaces of the assembly of the flexible PCB and the magneticsheet, in embodiments, protective and insulation coatings are furthercoated to complete making the single body of the flexible antennamodule.

Flexible Antenna Module in Smartphone

In embodiments, referring to FIGS. 2 and 10, the flexible antenna module100 is attached to the smartphone's rear cover 22. The connectorterminal pads 212 of the connector portion 208 are electricallyconnected to circuits in the smartphone 10.

Coil Antenna for MST Antenna

In embodiments, the inner and outer terminals of the first coil antennamay be connected to an MST circuit in the smartphone 10 such that thefirst coil antenna functions as an MST antenna or MST inductor. Magneticsecure transmission (MST) is also referred as magnetic stripetransmission or magnetic secure transmission as disclosed in US2016/0180120 A1 entitled “MAGNETIC SECURE TRANSMISSION DEVICE HARDWARE,”the entire disclosure of which is incorporated by reference herein. Inother embodiments, however, the second coil antenna may function as anMST antenna.

Coil Antenna for NFC Antenna

In embodiments, the inner and outer terminals of the second coil antenna206 are connected to an NFC circuit in the smartphone 10 such that thesecond coil antenna functions as an NFC antenna. Near FieldCommunication (NFC) is a standard allowing wireless communication in aRadio Frequency (RF) band between portable devices, such as smartphones,or between a portable device and a fixed device (an NFC terminal). Inother embodiments, however, the first coil antenna may function as anNFC antenna.

Operation of First and Second Coil Antennas

In embodiments, the smartphone with the antenna module has a controllerwhich operates the first and second coils as an MST antenna and an NFCantenna, respectively. The controller can operate the antenna coils suchthat the first coil antenna does not operate as an MST antenna while thesecond coil is operating as an NFC antenna. Similarly, the controlleroperates the antenna coils such that the second coil antenna does notoperate as an NFC antenna while the first coil is operating as an MSTantenna. In some embodiments, the antenna module may have three or morecoil antennas and the controller operates the three or more coilantennas such that only one coil antenna among the three or more coilantennas is operating and the other coil antennas is not working. Inembodiments, the controller does not allow two coil antennas among thethree or more coil antennas to work at the same time.

One Coil Antenna Functioning as Two Different Antennas

In embodiments, one of the coil antennas in the antenna module canfunction as both the MST antenna and the NFC antenna according tocontrol signals from the controller of the smartphone. In oneembodiment, the first coil antenna may function as the MST antenna inone period of time and the NFC antenna in another period of time. Thesecond coil antenna may function as another antenna, for example, awireless power charging antenna.

Smartphone's Rear Cover and Antenna Module

In embodiments, referring to FIGS. 2 and 10, the antenna module 100 isattached to the smartphone's rear cover 22 such that the head portion304 is interposed between the first PCB section 220 and the rear coveror rear wall 22 while the second PCB section 222 is interposed betweenthe base portion 302 and the rear cover 22. However, the invention isnot limited thereto. In other embodiments, the base portion isinterposed between the second PCB section and the rear cover while thefirst PCB section is interposed between the head portion and the rearcover.

Material of Rear Cover

In embodiments, referring to FIGS. 2 and 10, the smartphone 10 includesa rear cover 22. The rear cover can be made of non-metal material, forexample, a plastic resin. Generally, non-metal rear covers do notinterfere with wireless communications between antennas inside thesmartphone and devices outside the smartphone. In other embodiments, therear cover can be made of a metal which is electrically conductive andnon-magnetic. For example, copper or aluminum may be used for the rearcover. Generally, metal rear covers can interfere with wirelesscommunications between antennas inside the smartphone and devicesoutside the smartphone.

Metal Rear Cover of Smartphone

In embodiments, referring to FIGS. 2 and 10, when the rear cover 22 ismade of a metallic material, a smartphone 10 has a non-metal stripportion 28 in the rear cover and the antenna module is located withrespect to the non-metal strip portion 28 to reduce or minimizedinterference caused by the metallic rear cover.

Locational Relationship Between Magnetic Sheet and Non-Metal Portion ofRear Cover

In embodiments, referring to FIG. 10, the magnetic sheet 300 has a lowerend and the antenna module is located in the smartphone such that thelower end of the magnetic sheet 300 is sufficiently close to thenon-magnetic strip portion 28. This configuration allows theelectromagnetic signals generated from the first coil antenna 204 or thesecond coil antenna 206 to be transmitted through the non-magnetic stripportion 28. In other embodiments, as shown in FIGS. 11-14, the antennamodule is attached to the rear cover such that the magnetic sheet 300partially or completely overlaps or covers the non-magnetic stripportion 28.

Other Embodiments of Magnetic Sheet

In embodiments, the head portion has a width greater than that of thethrough hole. In this configuration, the head portion is bent whenpassing through the through hole. The magnetic sheet further includes aneck portion between the base portion and the head portion. The neckportion has a width smaller than that of the through hole.

Two or More Magnetic Sheet Pieces

In embodiments, instead of the magnetic sheet 300 discussed in theabove, two or more magnetic sheet pieces can be used. In embodiments,referring to FIG. 15, the two or more magnetic sheet pieces include afirst magnetic sheet piece 304′ and a second magnetic sheet piece 302′.In one embodiment, the first magnetic sheet piece 304′ can havesubstantially the same size and shape as the head portion 304 of themagnetic sheet 300 shown in the drawings. Further, the second magneticsheet piece 302′ can have substantially the same the same size and shapeas the base portion 302 of the magnetic sheet 300 shown in the drawings.As shown in FIG. 15, the first magnetic sheet piece 304′ and the secondmagnetic sheet piece 302′ are slightly spaced from each other and havean air gap therebetween.

Gap Between Two Magnetic Sheet Pieces

As shown in FIG. 15, in embodiments, the first magnetic sheet piece 304′includes a first edge and the second magnetic sheet piece 302′ includesa second edge which is opposing the first edge. The first and secondmagnetic sheet pieces 304′ and 302′ are slightly spaced from each otherto form a gap. The size of the gap (distance between the first edge andthe second edge) can be at or about 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm,0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8mm, 0.9 mm, 1 mm, 2 mm, 3 mm or 4 mm. In embodiments, the size of airgap may be within a range formed by selecting any two numbers listed inthe immediately previous sentence, e.g., between about 0.05 mm and about0.5 mm or between about 0.3 mm and about 1 mm. However, the invention isnot limited thereto. In another embodiment the first edge contacts thesecond edge. In other embodiments, the first magnetic sheet piece 304′and the second magnetic sheet piece 302′ can slightly overlap each otherin the through hole of the flexible PCB.

Material of First and Second Magnetic Sheet Pieces

In embodiments, the first and second magnetic sheet pieces 304′ and 302′together provide path for magnetic flux. Thus, like the magnetic sheet300, the first and second magnetic sheet pieces 304′ and 302′ are madeof soft magnetic material. Both the first and second magnetic sheetpieces are made of the same magnetic material. In other embodiments, thefirst magnetic sheet piece is made of a material different from that ofthe second magnetic sheet piece. For example, the first magnetic sheetpiece is made of a ferrite magnetic sheet and the second magnetic sheetpiece is made of a laminate of nanocrystal magnetic layers, or viceversa.

Two or More Stacked Magnetic Sheets

In embodiments, rather than using a single magnetic sheet 300 as shownin FIG. 7, two or more overlapping magnetic sheets can be used. In oneembodiment, as shown in FIG. 16, the two or more overlapping magneticsheets include a first magnetic sheet 3001 and a second magnetic sheet3003. The first magnetic sheet 3001 is made of a material different fromthat of the second magnetic sheet 3003. For example, the first magneticsheet 3001 is made of the ferrite magnetic sheet discussed above and thesecond magnetic sheet 3003 is made of a nanocrystal magnetic sheetlaminate discussed above. In some embodiments, more than two of theferrite magnetic sheets and more than two of the nanocrystal magneticsheet laminates are alternatingly stacked. The two or more overlappingmagnetic sheets can be bonded to each other to form a single body. Inother embodiments, the two or more magnetic sheets are not bonded untilthe flexible PCB and the magnetic sheets are made into a single body ofthe flexible antenna module as discussed below.

Operation of Plural Magnetic Sheets

The ferrite magnetic sheet and the nanocrystal magnetic sheet laminatemay have different magnetic properties or characteristics. Generally,the nanocrystal magnetic sheet laminate has permeability greater thanthat of the ferrite magnetic sheet. For this reason, the ferritemagnetic sheet shows performance higher than the nanocrystal magneticsheet laminate when working with an NFC antenna which works at afrequency greater than that of an MST antenna. On the other hand, thenanocrystal magnetic sheet laminate shows performance higher than theferrite magnetic sheet when working with an MST antenna. Thus, theoverlapping structure of different magnetic sheets works effectivelywhen the first coil antenna and the second coil antenna work fordifferent antenna functions, for example, an MST antenna and an NFCantenna as discussed below.

Locational Relationship Between Coil Portions and Magnetic Sheets

In embodiments, referring to FIGS. 6 and 22, when the first coil 204 isused for an MST antenna and the second coil 206 is used for an NFCantenna, both a ferrite magnetic sheet 3001 and a nanocrystal magneticsheet laminate 3003 that are stacked can be used. In one embodiment, theferrite magnetic sheet and the nanocrystal magnetic sheet have the sameshape and the same size such that they completely overlap each other,and the magnetic sheet assembly works as a single magnetic sheet shownin FIG. 7. In other embodiments, referring to FIGS. 16 and 17, theferrite magnetic sheet is longer than the nanocrystal magnetic sheetlaminate in the magnetic sheet assembly. When assembled with theflexible PCB, the ferrite magnetic sheet 3001 overlaps coil portions ofthe second coil antenna 206 which are located in the first PCB section220 whereas the nanocrystal magnetic sheet laminate 3003 does notoverlap the coil portions of the second coil antenna 206 which arelocated in the first PCB section 220, when viewed in the viewingdirection. However, the invention is not limited thereto. Inembodiments, when the first coil 204 is used for an NFC antenna and thesecond coil 206 is used for an MST antenna, the ferrite magnetic sheetis shorter than the nanocrystal magnetic sheet laminate such that theferrite magnetic sheet does not overlap coil portions of the second coilantenna 206 which are located in the first PCB section 220 whereas thenanocrystal magnetic sheet laminate overlaps the coil portions of thesecond coil antenna 206 which are located in the first PCB section 220when viewed in the viewing direction.

Modification of Embodiments Shown in FIGS. 3-17

The embodiments discussed above can be modified in various ways. Inmodified embodiments, the first coil antenna includes two or more coilselectrically connected to each other in series or in parallel in theflexible PCB. In one modified embodiment, the two or more coils of thefirst coil can be arranged side by side. In another modified embodiment,the two or more coils are arranged to overlap each other when viewed inthe viewing direction. Likewise, the second coil antenna may include twoor more coils electrically connected to each other in series or parallelin the flexible PCB.

Further Modification of Embodiments Shown in FIGS. 3-23

In one modified example, a smartphone antenna module includes a magneticsheet and a flexible PCB. The magnetic sheet includes a first sheetportion, a second sheet portion and an intermediate portion locatedbetween and connecting the first and second sheet portions. The flexiblePCB includes a first coil, a second coil and a third coil. When viewedin the viewing direction, the first and third coils are arranged side byside and the second coil surrounds both the first and third coils. Theflexible PCB has a first core area that the first coil surrounds whenviewed in the viewing direction and a second core area that the thirdcoil surrounds when viewed in the viewing direction. A through hole isformed in the first core area through the flexible PCB. The flexible PCBincludes a first PCB section, a second PCB section and a third PCBsection. The second PCB section is interposed between the first andthird PCB sections. The first and second PCB sections are locatedopposite to each other across the first core area, and the second andthird PCB sections are located opposite to each other across the secondcore area. No electrical connection is formed between the first coil andthe second coil within the flexible PCB and no electrical connection isformed between the second coil and the third coil in the flexible PCB.The flexible PCB and the magnetic sheet are integrated in a single,flexible body, in which the flexible PCB and the magnetic sheet arearranged relative to each other such that: the first sheet portion isplaced over the first PCB section and overlaps a first coil portion ofthe first coil formed in the first PCB section; the second sheet portionis placed under the second PCB section, overlaps a second coil portionof the first coil formed in the second PCB section and further overlapsa first coil portion of the third coil formed in the second PCB section,and at least part of the intermediate portion passes through the firstthrough hole. Further, the second sheet portion is placed under thethird PCB section and overlaps a second coil portion of the third coilformed in the third PCB section. The first and third coils may beconnected in the antenna module either in series or parallel. Thecurrent in the first coil and the current in the third coil flow eitherin the same rotational direction or in the opposite rotationaldirections.

Other Embodiments of Flexible PCB

In embodiments discussed above, the antenna module includes two coils inwhich one coil surrounds the other. The invention is not limitedthereto. In some embodiments, the antenna module includes three or morecoils. In one embodiment, two coils among the three or more coils arearranged side by side. In another embodiment, one of the three or morecoils surrounds another coil that surrounds one or more coils.

Electrical Connection Between Multiple Coils

In embodiments, each coil is electrically decoupled or disconnected fromother coils in the same antenna module, and each coil is used for aspecific antenna function different from the antenna functions of theother coils. For example, a first one of the multiple coils is used asan MST antenna, a second one of the multiple coils is used as an NFCantenna and a third one of the multiple coils is used as a wirelesspower charging antenna. In another embodiment, two coils among themultiple are electrically connected in the same antenna module. Forexample, to form a serially connected coil antenna as shown in FIG. 18Athe two coils may be connected in series. To form aconnected-in-parallel coil antenna as shown in FIG. 18B the two coilsmay be connected in parallel. In embodiments, the two coils connected toeach other can be used as a single antenna. For example, in an antennamodule that includes coil A, coil B and coil C, coil A and coil C areconnected to each other and can be used as an MST antenna while coil Bis decoupled from coil A and coil C and can be used as an NFC antenna.Details of configurations and functions of multiple coils in a singleantenna module are further discussed below.

Coil A, Coil B and Coil C in the Same Flexible PCB

In embodiments, referring to FIGS. 19-21, an antenna module 1100includes a flexible PCB 1200 and a magnetic sheet 1300. The antennamodule 1100 further includes coil 1204 (coil A), coil 1206 (coil B) andcoil 1208 (coil C) in the flexible PCB 1200. Coil A 1202 and coil C 1208are arranged side by side while coil B 1206 surrounds or encircles bothcoil A and coil C. The flexible PCB 1200 includes an upper edge and alower edge. The flexible PCB includes an upper through-hole 1202 thatcoil A 1204 surrounds and a lower through-hole 1203 that coil C 1208surrounds or encircles. The upper hole is located between the upper edgeand the lower hole, while the lower hole is located between the upperhole and the lower edge. The flexible PCB 1200 includes an upper PCBsection 1220 located between an upper edge 1232 and the upper hole 1202,a lower PCB section 1222 located between the lower edge 1232 and thelower hole 1203 and an intermediate PCB section 1224 located between theupper and lower holes. Referring to FIGS. 19-21, in embodiments, theupper PCB section 1220, the first hole 1202, the intermediate PCBsection 1224, the second hole 1203, and the lower PCB section 1222 areconsecutively arranged along an axis 1102 such that the axis 1102 passesthe upper PCB section 1220, the first hole 1202, the intermediate PCBsection 1224, the second hole 1203, and the lower PCB section 1222.

Coiling Direction of Coil A and Coil C

In one embodiment, as shown in FIG. 20, the conductive line of coil A1204 is coiled in a first coiling direction, for example, clockwisedirection as shown in FIG. 20. The conductive line of coil B 1206 iscoiled in a second coiling direction that is opposite to the firstcoiling direction. The conductive line of coil C 1208 is coiled in thefirst coiling direction. However, the invention is not limited thereto.In another embodiment, coil B may be coiled in the first coilingdirection. Coil A may be coiled in the second coiling direction. In thisdisclosure, the coiling direction is determined as a rotationaldirection when the conductive line is coiled from its inner terminal toits outer terminal.

Number of Turns of Each Coil

In embodiments, coil A 1204 includes one or more turns coiled toencircle or turn around the upper hole 1202 and coil C 1208 includes oneor more turns coiled to encircle or turn around the lower hole 1203.Coil B 2206 includes one or more turns coiled to encircle or turn aroundthe upper hole 1202, coil A 1204, the lower hole 1203 and coil C 1208.In embodiments, the number of turns of coil A 1204 may be the same asthat of coil A 204 shown in FIG. 6. In embodiments, the number of turnsof coil B 1206 may be the same as that of coil B 206 shown in FIG. 6.Further, the number of turns of coil C 1208 may be the same as that ofcoil A 1204. However, the invention is not limited thereto. The numberof turns of each coil may be modified or adjusted to provide an antennalength required for a specific antenna function.

Assembled with Magnetic Sheet

In embodiments, referring to FIGS. 19 and 21, a magnetic sheet 1300includes a base portion 1302, a head portion 1304 and a neck portion1306 connecting the base portion 1302 and head portion 1304. Whenassembled with the flexible PCB 1200, the head portion 1304 overlaps theupper PCB section 1220, the base portion 1302 overlaps the lower PCBsection 1222 and the neck portion 1306 overlaps the intermediate PCBsection 1224. Referring to FIGS. 19-21, when assembling the magneticsheet 1300 with the flexible PCB 1200, in one embodiment, the neckportion 1306 and the head portion 1304 go through the lower hole 1203,and then the head portion 1304 further goes through the upper hole 1202.Thus, when assembled, the head portion 1304 and the base portion 1302are placed on a sider of a major surface 1250 of the flexible PCB 1200while the neck portion 1306 is placed on a side of a major surface 1252of the flexible PCB that faces away from the first surface 1250.

Locational Relationship of Magnetic Sheet and Coil A and Coil C

In the assembled configuration, in embodiments, the conductive lineportions of coil A 1204 that are in the upper PCB section 1220 overlapthe head portion 1304 when viewed in the viewing direction. Theconductive line portions of coil C 1208 that are in the lower PCBsection 1222 overlap the base portion 1302 when viewed in the viewingdirection. The conductive line portions of coil A 1204 that are in theintermediate PCB section 1224 overlap the neck portion 1306 when viewedin the viewing direction. The conductive line portions of coil C 1208that are in the intermediate PCB section 1224 also overlap the neckportion 1306 when viewed in the viewing direction. In the illustratedembodiments, coil B 1206 does not include a conductive line portion thatoverlaps the head portion 1220 while coil B 1206 includes conductiveline portions that are in the lower PCB section 1222 and overlap thebase portion 1302 when viewed in the viewing direction. When the antennamodule 1100 is assembled in a smartphone 10 as shown in FIG. 21, theantenna module 1100 is arranged such that the first surface 1250 of theflexible PCB 1200 faces a rear cover 22 of the smartphone. Thus, thehead portion 1304 is located between the rear cover 22 and the upper PCBsection 1220 and the base portion 1302 is located between the rear cover22 and the lower PCB section 1222. Since the neck portion 1306 islocated over the second surface 1252, the intermediate PCB section 1224includes a portion located between the rear cover 22 and the neckportion 1306. However, the invention is not limited thereto. When theantenna module 1100 is arranged such that the second surface 1252 of theflexible PCB 1200 faces the rear cover 22 of the smartphone, the neckportion may be located between the intermediate PCB section 1224 and therear cover 22.

Size and Shape of Magnetic Sheet

In the embodiments in FIGS. 19 and 21, the head portion 1304, the neckportion 1306 and the base portion 1302 have substantially the samewidth. However, the invention is not limited thereto. In anotherembodiment, the head portion has a width (measured in horizontaldirection) the same as that of the neck portion, but smaller than thatof the base portion. In another embodiment, each of the base, neck andhead portions has a width different from those of the others.

Series Connection and Current Direction

In embodiments shown in FIG. 20, coil A 1204 and coil C 1208 areelectrically connected to each other. For example, the outer terminalsof coil A 1204 and coil C 1208 are connected while the inner terminal ofeach of coil A 1204 and coil C 1208 is connected to one of terminal pads1262 and 1264 in a connector portion 1210 of the flexible PCB 1200. Thisconnection configuration provides a series circuit of coil A and coil Cas shown in FIG. 18A. When the conductive lines of coil A and coil C arecoiled in the same coiling direction as shown in FIG. 20 and coil A andcoil C are further connected in series as illustrated in FIG. 18A, thecurrent signal of coil A 1204 flows in a first rotational currentdirection while the current signal of coil C 1208 flows in a secondrotational current direction that is opposite to the first rotationalcurrent direction. For example, as indicated in FIG. 20 usingarrowheads, the current of coil A 1204 flows in the clockwise directionwhile the current of coil C 1208 flows in the counterclockwise directionwhen viewed in the viewing direction. In this current flowconfiguration, in conductive line portions of coil A 1204 and coil C1208 which overlap the neck portion 1306 of the magnetic sheet, thecurrent flows in the same linear direction as shown in FIG. 20.

Magnetic Flux in Magnetic Sheet

The current flow as discussed above and shown in FIG. 20 would generatemagnetic flux that extends from the head portion 1304 to the baseportion 1302 via the neck portion 1306 of the magnetic sheet 1300 asindicated as arrows. Further, the density of the magnetic flux generatedin the magnetic sheet would be sufficient such that the smartphonewirelessly communicates with an outside device via an antenna havingcoil A and coil C. If the current of coil A and coil C flows in the samerotational direction, the current flow of conductive line portions ofcoil A that overlap the neck portion would be in a linear directionopposite to another linear direction of current flow of the conductiveline portions of coil C that overlap the neck portion, and then, themagnetic flux generated in the head and base portions would extend outof the neck portion toward air.

Other Embodiments of Coiling Direction and Current Direction

In alternative embodiments, the coiling direction of coil A is differentfrom that of coil C. In this embodiment, the outer terminal of coil A isconnected to the inner terminal of coil C. The inner terminal of coil Aand the outer terminal of coil C are connected to terminal pads of theconnector portion, respectively. This connection configuration canensure that the current of coil A flows in a rotational currentdirection opposite to that of coil C.

Coil A and Coil C for MST Antenna and Coil B for NFC Antenna

In embodiments illustrated in FIGS. 19-21, coil A 1204 and coil C 1208form a single coil antenna functioning as an MST antenna while coil B1206 functions as an NFC antenna. In one embodiment, the magnetic sheetmay include both a nanocrystal magnetic sheet laminate and a ferritemagnetic sheet.

Additional Coil in Different Layer of Flexible PCB

In embodiments, the flexible PCB may include two or more layers, each ofwhich includes at least one coil. For example, referring to FIGS. 19, 22and 23, the antenna module 1100 includes a flexible PCB 1200′ whichincludes a bottom layer 1270, a top layer 1272 over the bottom layer1270 and an insulation layer interposed therebetween. In embodiments,the top layer 1272 is placed over the bottom layer 1270 such that theupper holes 1202 of the upper and lower layers are aligned and the lowerholes 1204 of the upper and lower layers are aligned. The bottom layer1270 includes coil 1204 (coil A), coil 1206 (coil B) and coil 1208 (coilC), and the top layer 1272 includes coil 1210 (coil D). In embodiments,the coiling direction and the current flow direction of coil A, coil Band coil C illustrated in FIG. 22 are the same as those in theembodiments illustrated in FIG. 20. Further, as shown in FIG. 25, thelocational relationship between the magnetic sheet 1300 and each of coilA 1204, coil B 1206 and coil C 1208 is the same as the locationalrelationship illustrated in FIG. 21. In the discussion of embodiments,the terms “top” and “bottom” do not refer to their absolute location. Insome circumstances, for example, an item labeled with term “top” may belocated lower or under an item labeled with the term “bottom.

Coil D of Top Layer

As shown in FIG. 22, the top layer 1272 includes coil D 1210 surroundingthe upper hole 1202. As shown in FIG. 22, coil D 1210 is coiled in thesecond coiling direction, for example, counterclockwise direction, whichis opposite to the coiling direction of coil A and coil B. The outerterminal of coil D 1210 is connected to one of the terminal pads of theconnector portion 1210. The inner terminal of coil D 1210 is connectedto the inner terminal of coil A 1204. As shown in FIG. 22, the top layer1272 further includes a plurality of conductive line segments 1280 and1282. Two end terminals of each conductive line segment 1280 areconnected to coil C 1208 to form a parallel connection between coil C1208 and each of the conductive line segment 1280 as shown in FIG. 23A.Two end terminals of each conductive line segment 1282 are connected tocoil B 1206 to form a parallel connection between coil B 1206 and eachof the conductive line segment 1282 as shown in FIG. 23B. The connectionof conductive line segments can reduce resistance in coil B 1206 andcoil C 1208. FIG. 24 shows an example of a conductive line patterndesign of the top layer 1272′ and bottom layer 1270′ to form coil A,coil B, coil C and coil D and conductive line segments.

Locational Relationship Between Coil D and Magnetic Sheet

In embodiments, referring to FIG. 25, when the magnetic sheet 1300 isassembled with the flexible PCB 1200′, the conductive line portions ofcoil D 1210 that are in the upper PCB section 1220 overlap the headportion 1304 when viewed in the viewing direction. The conductive lineportions of coil D 1210 that are in the intermediate PCB section 1224overlap the neck portion 1306 when viewed in the viewing direction. Therelationship between the magnetic sheet 1300 and each of coil A, coil Band coil C 1204, 1206 and 1208 is the same as that of the embodimentsillustrated in FIGS. 20 and 21.

Series Connection and Current Direction

In embodiments shown in FIG. 22, coil A 1204, coil C 1208 and coil D1210 are electrically connected to each other in series. The innerterminal of coil A 1204 is connected to the inner terminal of coil D1210 through a via. The current flows from a terminal pad to anotherterminal pad of the connector portion 1210 via coil D 1210, coil A 1204and coil C 1208 in turn. In one embodiment, the current of coil A 1204and coil D 1210 flows in a first rotational current direction, while thecurrent of coil C 1208 flows in a second rotational current directionthat is opposite to the first rotational current direction. For example,as indicated in FIG. 22 using arrowheads, the current signal of coil Aand coil D flows in the clockwise direction while the current signal ofcoil C 1208 flows in the counterclockwise direction. This current flowconfiguration shown in FIG. 22 would cause the magnetic flux directionthe same as that caused by the current flow configuration shown in FIG.20; however, its density would be greater than the density in theantenna module shown in FIG. 21. In embodiments, when coil A, coil C andcoil D form an antenna functioning as an MST antenna, since coil D 1210is formed in the top layer, the antenna module can provide the antennalength for the MST antenna while having a reduced or compact size.

Other Embodiments Shown in FIGS. 26-28

In the embodiments discussed above, coil B surrounds coil C, but theinvention is not limited thereto. In some embodiments illustrated inFIGS. 26-28, an antenna module includes coil 1204 (coil A), coil 1206″(coil B) and coil 1208 (coil C), and coil B 1206″ and coil C 1208 arearranged side by side while coil B 1206″ surrounds coil A 1204.Referring to FIGS. 26-28, between coil A and coil C 1204 and 1208, theconductive line portions of coil B 1206″ extend, while coil A and coil Care connected to each other via a connector line formed in another layerwhich is different from a layer in which coil A, coil B and coil C areformed. In embodiments, the coiling direction and the current directionof coil A, coil B and coil C shown in FIG. 25 are the same as thoseshown in FIG. 20.

Locational Relationship of Coils and Magnetic Sheet Shown in FIGS. 26-28

In embodiments, referring to FIGS. 27 and 28, coil B 1206″ includes theconductive line portions that are in the upper PCB section 1220 andoverlap the head portion 1304″. Further, coil B 1206″ includesconductive line portions that are in the intermediate PCB section 1224and overlap the neck portion. The locational relationship of themagnetic sheet and coil A and coil C are the same as that of theembodiments illustrated in FIGS. 19-21. In the embodiments illustratedin FIGS. 26 and 28, the head portion 1304″ of the magnetic sheet 1300″is located close to or adjacent the conductive line portions of coil B1206″ that are in the upper PCB section 1220. This configuration wouldbe advantageous to generate magnetic flux with a higher density in themagnetic sheet by current applied to coil B 1206″ than when the magneticsheet is distant from conductive line portions of coil B that are in theupper PCB section 1220. In the embodiments shown in FIGS. 26-28, theconductive line portions of coil B 1206″ in the upper PCB section 1220are over a first surface 1350 of the magnetic sheet while the conductiveline portions of coil B 1206″ in the intermediate PCB section 1224 areover a second surface 1352 of the magnetic sheet 1300″. Thisconfiguration would ensure that the magnetic flux generated in themagnetic sheet 1300 by current of coil B 1206″ extends from the headportion toward the base portion via the neck portion.

Embodiments Shown in FIGS. 26, 29 and 30

In embodiments, referring to FIGS. 26, 29 and 30, an antenna moduleincludes coil 1204 (coil A), coil 1206′″ (coil B), coil 1208 (coil C)and coil 1212 (coil E). Coil A and coil C 1204 and 1212 are arrangedside by side as like embodiments shown in FIGS. 20, 22 and 27. In theembodiments illustrated in FIG. 29, however, coil B 1206′″ surroundscoil A 1202, but does not surround coil C 1208. Coil E 1212 surroundscoil C 1208. Coil B 1206′″ and coil E 1212 are arranged side by side. Inthe embodiments illustrated in FIG. 29, the electrical connection,coiling direction and current direction of coil A and coil C 1204 and1208 are the same as those in embodiments illustrated in FIG. 27. Coil B1206′″ and coil E 1212 are electrically connected to each other inseries as shown in FIG. 18A. The conductive lines of coil B and coil Eare coiled in the same coiling direction, for example, thecounterclockwise direction. Further, the inner terminals of coil B andcoil E are connected to each other via a connector line formed in alayer different from another layer in which coil B and coil E areformed. In this connection configuration, the current of coil B 1206′″flows in a rotational current direction opposite that of the currentflow of coil E 1212. Thus, in conductive line portions of coil B andcoil E which overlap the neck portion 1306 of the magnetic sheet 1300′″when viewed in the viewing direction, the current flows in the samelinear direction as shown in FIG. 29.

Locational Relationship of Coils and Magnetic Sheet Shown in FIGS. 29and 30

In embodiments, referring to FIGS. 26, 29 and 30, coil B 1206′″ includesthe conductive line portions that are in the upper PCB section 1220′″and overlap the head portion 1304′″, and further includes conductiveline portions that are in the intermediate PCB section 1224 and overlapthe neck portion 1306. Similarly, coil E 1212 includes the conductiveline portions that are in the intermediate PCB section 1224 and overlapthe neck portion 1306, and further includes conductive line portionsthat are in the lower PCB section 1222 and overlap the base portion1302. The locational relationship of the magnetic sheet 1300′″ and coilA and coil C are the same as that of the embodiments illustrated inFIGS. 21, 25, and 28. In the embodiments illustrated in FIGS. 29 and 30,when the current of coil B 1206′″ flows in the clockwise direction themagnetic flux in the magnetic sheet extends from the head portion to theneck portion. Further, since the current of coil E 1212 flows in thecounterclockwise direction, the magnetic flux in the magnetic sheet1300′″ extends from the neck portion 1306 to base portion 1302. As aresult, the above current flow configuration would ensure that themagnetic flux generated in the magnetic sheet by current of coil B andthe magnetic flux generated in the magnetic sheet by current of coil Eextend in the same directions, for example, from the head portion tobase portion via the neck portion. Also, the head portion 1304′″ of themagnetic sheet is located close to or adjacent the conductive lineportions of coil B that are in the upper PCB section.

Usage of Coil A, Coil B, Coil C and Coil E Shown in FIGS. 29 and 30

Similarly to embodiments discussed above, coil A and coil C 1204 and1208 of the flexible PCB 1200′″ can be used as an MST antenna. In theembodiments shown in FIGS. 29 and 30, coil B 1206′″ and coil E 1212 canbe used as an NFC antenna. In the embodiments, discussed above, coil Aand coil C 1204 and 1208 are connected to each other in series, and coilB 1206′″ and coil E 1212 are connected to each other in series. However,the invention is not limited thereto. For example, to provide a properlength of antennas, the connections may be modified to parallelconnections. Further, the number of turns of each coil may be modifiedor adjusted. In other embodiments, coil A and coil C may be used as anNFC antenna and coil B and coil E may be used as an MST antenna.

Modification to Embodiments Shown in FIGS. 29 and 30

Embodiments shown in FIGS. 29 and 30 may be modified. In the modifiedembodiments, the antenna module further includes coil D and coil Fformed in a bottom layer of the flexible PCB whereas coil A, coil B,coil C and coil E are formed in a top layer which is disposed over thebottom layer. The structure of coil D and its connection with coil A andcoil C are the same as those in the embodiments illustrated in FIGS.22-25. Coil F is formed over coil B and coiled in a coiling directionopposite to the coiling direction of coil B when viewed in the viewingdirection. Coil B, coil E and coil F are connected in series, and thecurrent of coil B and coil F flows in the same rotational direction whenviewed in the viewing direction. This addition of coil D and coil Fwould be able to increase the density of magnetic flux generated in themagnetic sheet and further increase the strength of antenna signals.But, the invention is not limited to the above embodiments. For example,coil A and coil C may be connected to each other in parallel as shown inFIG. 18B. Coil A and coil D may be connected to each other in parallel.Similarly, coil B and coil E may be connected to each other in parallel.Coil B and coil F may be connected to each other in parallel.

Decoupled Multiple Coils

In the embodiments discussed above, two or more coils are connected toeach other in the antenna module either in series or parallel. However,the invention is not limited thereto. In alternative embodiments, thecoils are decoupled from one another, and each coil functions as anantenna different from antennas that the other coils function as whenassembled in a smartphone and connected to circuits in the smartphone.Each coil can be used as one of an MST antenna, an NFC antenna and otherantenna that uses a coil antenna, such as wireless charging antenna.

Coil Antenna for Wireless Power Charging Antenna

In embodiments, one of coils may be connected to a wireless powercharging circuit in the smartphone such that the coil functions as awireless power charging antenna or wireless power charging inductor. Inembodiments, the wireless power charging circuit and the coil antennamay form a wireless power charging system according to the standardunder Wireless Power Consortium (WPC). In other embodiments, thewireless power charging circuit and the coil antenna may form a wirelesspower charging system according to the standard under Power MattersAlliance (PMA).

Modification of Embodiments Shown in FIGS. 19-30

The embodiments discussed above can be modified various ways. In theembodiments shown in FIGS. 19-30, the head portion of the magnetic sheetis placed over the upper PCB section of the flexible PCB, the neckportion is placed under the intermediate PCB section, and the baseportion is placed over the lower PCB section. In the modified example,the base portion may be placed over the lower PCB section, while thehead portion is placed over the upper PCB section and the neck portionis placed under the intermediate PCB section. In this modified example,the lower hole is not provided at the second core area that coil Csurrounds while the upper hole is provided at the first core area thatcoil A surrounds when viewed in the viewing direction.

Separate Coil Outside Flexible PCB

In the embodiments discussed above, the coils are formed in one flexiblePCB. However, the invention is not limited thereto. An antenna modulemay include one or more coils that are not part of the flexible PCB. Theone or more coils comprise coil G that is not part of the flexible PCBand placed over the magnetic sheet. In one embodiment, the portion ofcoil G when viewed in the viewing direction. Coil G may be placedpartially or entirely over the magnetic sheet and may include at least aportion that is interposed between the magnetic sheet and the rear coverof the smartphone when assembled in the smartphone. In the otherembodiment, coil G is placed to overlap both the flexible PCB and themagnetic sheet. Further, in one embodiment, coil G may be a windingantenna as shown in FIGS. 32-34. Coil G may be disposed in aside-by-side relationship with the coils in the flexible PCB, and theflexible PCB may further include, for example, a bridge portion as shownin FIGS. 32-34 for providing an electrical connection between coil G anda connector portion of the flexible PCB.

Two Flexible PCBs

In embodiments, the antenna module includes a first flexible PCB and asecond flexible PCB. The first flexible PCB includes multiple coils, forexample, coil A and coil B as in embodiments discussed above, and thesecond flexible PCB includes a further coil (coil G). When making theantenna module, in embodiments, the first flexible PCB and the magneticsheet are assembled as in the embodiments discussed above, and thesecond flexible PCB is placed over or engaged with the magnetic sheet,and then, the first and second flexible PCBs and the magnetic sheet areintegrated into a single body of the antenna module.

Locational Relationship Between Second Flexible PCB and First FlexiblePCB

In embodiments, the second flexible PCB includes a central portion thatcoil G surrounds. The second flexible PCB 5250 may have a hole at thecentral portion as shown in FIG. 31. In one embodiment, the secondflexible PCB 5250 is placed over the first flexible PCB 5200 such thatsubstantially the entire portion of the second flexible PCB 5250overlaps the first flexible PCB 5200. In the embodiment shown in FIG.31, the magnetic sheet 5300 passes through the holes of the first andsecond flexible PCBs. In another embodiment, as illustrated using dottedlines in FIG. 31, the second flexible PCB 5250′ is placed over the firstflexible PCB and its hole overlaps another hole of the first flexiblePCB 5200. In the other embodiments, as illustrated using dotted lines inFIG. 31, the second flexible PCB 5250″ is placed over the magnetic sheetand does not overlap the first flexible PCB 5200 when viewed in theviewing direction. However, the invention is not limited thereto. Inalternative embodiments, the second flexible PCB is placed over themagnetic sheet to partially overlap the first flexible PCB when viewedin the viewing direction. In the embodiments shown in FIG. 31, thesecond flexible PCB 5250″ is located under the base portion of themagnetic sheet. However, the invention is not limited thereto. In oneembodiment, the second flexible PCB 5250″ may be located over the baseportion of the magnetic sheet. In another embodiment, the base portionof the magnetic sheet passes through the hole of the second flexible PCB5250″.

Connection Between First and Second Flexible PCB

In embodiments, referring to FIG. 31, the first flexible PCB 5200includes a connector portion 5210 and the second flexible PCB 5250″includes a bridge portion 5260. The connector portion 5210 extends froma body portion of the first flexible PCB. The connector portion includesa plurality of terminal pads formed at an end portion of the connectorportion 5210. In embodiments, the connector portion includes three ormore pairs of the terminal pads. A first pair of terminal pads among theplurality of terminal pads are connected to the inner and outerterminals of coil A of the first flexible PCB via connector lines. Asecond pair of terminal pads among the plurality of terminal pads areconnected to the inner and outer terminals of coil B of the firstflexible PCB via connector lines. The bridge portion is located at alocation close to or overlapping the first flexible PCB. The bridgeportion includes two terminal pads which are connected to the inner andthe outer terminal of coil G of the second flexible PCB. A third pair ofterminal pads in the connector portion 5210 is connected to the terminalpads contacting the terminal pads of the bridge portion via connectorlines formed in the first flexible PCB. When the second flexible PCB isplaced over the assembly of the first flexible PCB and the magneticsheet, in one embodiment, each terminal pad of the first flexible PCBcontacts and bonded to the corresponding terminal pad of the bridgeportion of the second flexible PCB for allowing electrical connectiontherebetween. They are bonded to each other by welding or soldering. Thecontact and electrical connection between the terminal pads of the firstflexible PCB and the terminal pads of the bridge portion can bemaintained after the first and second flexible PCBs and the magneticsheet are integrated into a single body. In another embodiment, thebridge portion is formed in the first flexible PCB rather than thesecond flexible PCB. In embodiments, when assembled in the smartphone,the terminal pads of the connector portion 5210 are connected tocounterpart connection terminals of the smartphone circuit forelectrically connecting coil A, coil B and coil G to the smartphonecircuit.

Usage of Coils in First and Second Flexible PCBs

In the embodiments discussed above, coil A, coil B and coil G are usedas an MST antenna, an NFC antenna and a wireless power charging antenna,respectively. However, the invention is not limited thereto. Inembodiments, when the antenna module is assembled in a smartphone, eachof coil A, coil B and coil C is used as either one of the MST antenna,the NFC antenna and the wireless power charging antenna. In one example,coil B antenna functions as an MST antenna, coil G antenna functions asan NFC antenna and coil A functions as a wireless charging transformer.In another example, when the antenna module is assembled in asmartphone, coil G antenna functions as an MST antenna, coil A functionsas an NFC antenna and coil B antenna functions as a wireless powercharging transformer. When coil G antenna is used as a wireless chargingantenna, in embodiments, coil G is placed over the magnetic sheet andthe magnetic sheet does not pass through a hole that coil G surrounds.

Coil U, Coil W and Coil V in the Same Flexible PCB

In embodiments, referring to FIGS. 35-39, an antenna module 2100includes a flexible PCB 2200 and a magnetic sheet 2300. The antennamodule 2100 further includes coil 2204 (coil U), coil 2206 (coil W) andcoil 2208 (coil V) in the flexible PCB 2200. The flexible PCB 2200includes a through-hole 2202. The through-hole 2202 is located betweenthe upper edge 22002 and the lower edge 22004. The flexible PCB 2200includes an upper PCB section 2220 located between an upper edge 2230and the through-hole 2202, and a lower PCB section 2222 located betweenthe lower edge 2232 and the through-hole 2202. Referring to FIGS. 35-39,in embodiments, the upper PCB section 2220, the through-hole 2202, andthe lower PCB section 2222 are arranged along an axis 2102 such that theaxis 2102 passes the upper PCB section 2220, the through-hole 2202, andthe lower PCB section 2222 in order.

Coil U

In embodiments, coil U 2204 is formed of a printed electricallyconductive wire and coiled to surround or turn around the through-hole2202. Coil U 2204 may have one or more turns that completely turn aroundthe through-hole 2202. Referring to FIG. 37, coil U 2204 includes fourturns; however, the invention is not limited thereto. In anotherembodiment, coil U may have 1, 2, 3, 5, 6, 7, 8 and 9 turns. Inembodiments, coil U 2204 may have the same configuration as those ofcoils 204 and 1204 shown in FIGS. 6 and 26. In one embodiment, thecoiled conductive wire of coil U 2204 may be printed in a single layerof the flexible PCB. In other embodiments, the coiled conductive wire ofcoil U 2204 may include wire portions printed in multiple layers of theflexible PCB and vias connecting the wire portions printed in multiplelayers.

Coil V

Referring to the embodiment of FIG. 37, coil U 2204 and coil V 2208 arelocated by side by side. In one embodiment, coil V 2208 is located inthe lower PCB section 2222 and does not extend beyond the lower PCBsection 2222. In the illustrated embodiments, coil V does not include aportion overlapping coil U 2204. Coil V 2208 is formed of a printedelectrically conductive wire. As shown in FIG. 37, coil V 2208 is coiledin a circular-spiral shape. Coil V 2208 has one or more turns. In oneembodiment, the coiled conductive wire of coil V 2208 may be printed ina single layer of the flexible PCB. In other embodiments, the coiledconductive wire of coil V 2208 may include wire portions printed inmultiple layers of the flexible PCB and vias connecting the wireportions printed in multiple layers.

Coil W

In embodiments, coil W 2206 is formed of a printed electricallyconductive wire. Referring to FIG. 37, two outer turns 22064 of coil W2206 extend along the periphery of the flexible PCB 2200. An inner turn22068 of coil W 2206 includes a line segment 22060 that crosses coil Vas shown in FIG. 37. In one embodiment, the line segment 22060 passesthrough the center of coil V 2208 and extends generally perpendicular tothe axis 2102. The line segment 22060 is insulated from coil V 2208. Inembodiments, coil W 2206 may have the same configuration as those ofcoil 1206 shown in FIG. 20. In one embodiment, the coiled conductivewire of coil W 2206 may be printed in a single layer of the flexiblePCB. In other embodiments, the coiled conductive wire of coil W 2206 mayinclude wire portions printed in multiple layers of the flexible PCB andvias connecting the wire portions printed in multiple layers. AlthoughFIG. 37 shows that two outer turns 22064 extend along the periphery ofthe PCB, the invention is not limited thereto. The entire turns of coilW may have a shape different from that of the periphery of the PCB 2200.

Coil W Surrounding Through-Hole, Coil U and Coil V

In embodiments, coil W 2206 includes one or more turns that surround orturn around all of coil U 2204, the through-hole 2202 and coil V 2208,as shown in FIG. 37. Coil V 2208 is located between coil U 2204 and lineportions 22062 adjacent the lower edge of the flexible PCB. In theillustrated embodiment, two turns 22064 of coil W 2206 extend along theperiphery to surround or turn around all of the through-hole 2202, theentire turns of coil U 2204 and the entire turns of coil V 2208. Coil W2206 further include a single inner turn 22068 that surrounds or turnsaround both the through-hole 2202 and the entire turns of coil U.However, one half of coil V 2208 is surrounded by the single inner turn22068 and the other half of coil V 2208 is located outside the singleinner turn 22068.

Shape of Magnetic Sheet

In embodiments, referring to FIGS. 35-39, a magnetic sheet 2300 includesa base portion 2302, a head portion 2304 and a neck portion 2306connecting the base portion 2302 and head portion 2304. In theembodiment illustrated in FIG. 38, the head portion 2304 has a width asmeasured in a horizontal direction the same as that of the neck portion2306, and the magnetic sheet 2300 does not a structure dividing the headportion and the neck portion. The base portion 2302 has a width greaterthan those of the head and neck portions. In other embodiments, the headportion has a width greater than that of the neck portion. The headportion may have a width even greater than that of the through-hole suchthat the head portion is deformed for inserting the head portion throughthe through-hole. In one embodiment, the head portion has a widthsmaller than that of the neck portion. In another embodiment, the base,neck and head portions have the same width.

Assembly of Magnetic Sheet and Flexible PCB Including Coils U, V and W

When engaged or assembled with the flexible PCB 2200, the head portion2304 overlaps the upper PCB section 2220; the base portion 2302 overlapsthe lower PCB section 2222; and the neck portion 2306 overlaps thethrough-hole 2202. When assembling the magnetic sheet 2300 with theflexible PCB 2200, in one embodiment, the head portion 2304 go throughthe through-hole 2202 from the side of a surface 2350 of the flexiblePCB 2200 to the side of the opposite surface 2252 of the flexible PCB2200 that faces away from the surface 2350. When assembled, the baseportion 2302 is placed on the surface 2350 of the flexible PCB 2200while the head portion 2302 is placed on the opposite surface 2252 ofthe flexible PCB. In FIGS. 35-39, the flexible PCB and the magneticsheet are shown to be thicker than actual products for the sake ofillustration; however, the invention is not limited to the thicknessshown in the drawings.

Locational Relationship of Components of Antenna Module when Assembledin a Smartphone

Referring to FIG. 39, when the antenna module 2100 is installed in asmartphone 10, the surface 2252 of the flexible PCB 2200 faces a rearcover 22 of the smartphone. Thus, the head portion 2304 is locatedbetween the rear cover 22 and the upper PCB section 2220. Since the baseportion 2302 is located on the surface 2350, the lower PCB section 2222is located between the rear cover 22 and the base portion 2302. However,the invention is not limited thereto. When the antenna module isarranged such that the surface 2350 of the flexible PCB 2200 faces therear cover 22 of the smartphone, the base portion may be located betweenthe lower PCB section 2222 and the rear cover 22.

Locational Relationship of Magnetic Sheet and Coil U

Referring to FIG. 37, coil U 2204 includes, for example, four conductivelines that are located in the upper PCB section 2220 and extend along anupper edge 22022 of the through-hole 2202. In the illustratedembodiment, each of the four lines of coil U in the upper section 2220overlaps the head portion 2304. But, the invention is not limitedthereto. In another embodiment, at least one of the four lines of coil Udoes not overlap the head portion 2304. Coil U 2204 further includesfour lines that are located in the lower PCB section 2222 and extendalong a lower edge 22024 of the through-hole 2202. In the illustratedembodiment, each of the four lines of coil U in the lower PCB section2222 overlaps the base portion 2304.

Locational Relationship of Magnetic Sheet and Coil V

Referring to FIGS. 37 and 39, the entire turns of coil V 2208 arelocated in the lower PCB section 2222 and overlap the base portion 2302when viewed in the viewing direction. In FIG. 38, the entire portion ofcoil V 2208 is located between the base portion 2302 and the rear cover22 of the smartphone.

Locational Relationship of Magnetic Sheet and Coil W

Referring to FIGS. 37 and 39, coil W 2206 includes three lines 22069that are located in the upper PCB section 2220 and extend along theupper edge 22002 of the flexible PCB. In embodiments, none of the threelines of coil W 2206 in the upper PCB section 2220 overlaps the headportion 2304. But, the invention is not limited thereto. In otherembodiments, at least one of the three lines of coil W 2206 in the upperPCB section 2220 overlaps the head portion 2304. Referring to FIG. 37,coil W 2206 further includes three lines 22062 and 22060 that arelocated in the lower PCB section 2222. In one embodiment, each of thethree lines of coil W located in the lower PCB section 2222 overlaps thebase portion 2308 when viewed in the viewing direction. In anotherembodiment, the entire portions of coil W that are located in the lowerPCB section 2222 overlap the base portion 2302.

No Electric Connection Among Coils U, V and W of Flexible PCB

In embodiments, referring to FIG. 37, there is no electric connectionamong coil U 2204, coil W 2206 and coil V 2208 in the flexible PCB.Specifically, each of coil U 2204, coil W 2206 and coil V 2208 has aninner terminal and an outer terminal. Each of the inner and outerterminals of coil U 2204, coil W 2206 and coil V 2208 is connected to acorresponding one among connector terminal pads 2242 formed in aconnector portion 2240 of the flexible PCB 2200.

Magnetic Flux in Magnetic Sheet

Referring to FIG. 37, when current flows through coil U 2204, magneticflux are generated to generally extend from the head portion 2304 to thebase portion 2302 via the neck portion 2306 of the magnetic sheet 2300.In embodiments, when current flows through coil V 2208, magnetic fluxare generated to generally extend radially from the peripheral area ofthe base portion to the central portion of coil V 2208.

Coil U for MST Antenna, Coil V for Wireless Charging and Coil W for NFCAntenna

In embodiments, when the antenna module is installed in a smartphone,coil U 2204 is connected to an MST circuit in the smartphone andfunctions as an MST antenna. Coil V 2208 is connected to a wirelesscharging circuit for charging a battery in the smartphone and functionsas a wireless charging antenna. Coil W 2206 is connected to an NFCcircuit in the smartphone and functions as an NFC antenna. Inembodiments, the smartphone includes a controller which operates coil U,coil V and coil W as an MST antenna, a wireless charging antenna and anNFC antenna, respectively. The controller can operate coils U, V and Wsuch that coil U and coil W does not operate while coil V is operatingas a wireless charging antenna. Similarly, the controller operates coilsU, V and W such that coil W and coil V do not operate while coil U isoperating as an MST antenna. The controller can also operate coil U, Vand W such that coil U and coil V does not operate while coil W isoperating as an NFC antenna.

Coils Printed in Multiple Layers of Flexible PCB

The flexible PCB may include two or more layers. For example, a coil (atleast one turn of printed line) is formed in one layer, and another coilis formed in another layer. Further, another coil may be formed inanother layer of the two or more layers. One or more vias interconnectthese coils such that these coils form a serial connection for providinga serially connected coil antenna. In other embodiment, two or morecoils of different layers are connected by parallel connection toprovide two more coil antennas that are parallel connected. In oneembodiment, a coil is formed in each of the two or more layers. Inanother embodiment, at least one layer of the flexible PCB does notinclude a coil.

Printed Coil Segments

In embodiments, at least one of the multiple layers contain a printedline (or printed coil segment) that does not form a turn. The printedcoil segment of a layer may be connected to another coil segment ofanother layer or to a coil of another layer via one or more vias.

Embodiments Shown in FIGS. 40-44

For example, referring to FIGS. 40-44, an antenna module 2100′ includesa flexible PCB 2200′ which includes a bottom layer 2270, a top layer2272 and an insulation layer interposed therebetween. In embodiments,the top layer 2272 is placed over the bottom layer 2270 such that thethrough-holes 2202 of the top and bottom layers are aligned. The bottomlayer 2270 includes coil 2204′ (coil U), coil 2206′ (coil W), and linesegments of coil V (for example, line segments 22085, 22086 and 22087 ofcoil V shown in FIGS. 43 and 44). The top layer 2270 includes coil 2210(coil X), line segments for coil W, and line segments of coil V (forexample, line segments 22081, 22082 and 22083 shown in FIGS. 42 and 44).In the discussions of embodiments illustrated in FIGS. 40-44, the terms“top” and “bottom” do not refer to their absolute location. In somecircumstances, for example, an item labeled with term “top” may belocated lower or under an item labeled with the term “bottom.” Thelocational relationship between the magnetic sheet 2300′ and each ofcoil U, coil W and coil V is the same as the locational relationshipillustrated in FIGS. 37 and 39.

Connections of Coils in Multiple Layers in FIGS. 40-44

In embodiments, coil U and coil X are connected to each other in serieslikewise coils 1204 and 1210 of the embodiments shown in FIG. 22.Referring to FIGS. 42-44, line segments 22081, 22082, 22083, 22085,22086 and 22087 are connected via vias to form coil V. Each via connectscorresponding two points, among the points P1-P16. In embodiments, linesegments 22060 formed in the top layer are connected to coil 2206′ (coilW) formed on the bottom layer via vias likewise coil 1206 and linesegments of the embodiments shown in FIGS. 22 and 23B. In theembodiments illustrated in FIGS. 40-44, coil W does not include a linesegment that crosses coil V, but not limited thereto. In embodiments,the magnetic sheet 2300′ shown in FIGS. 40 and 41 is the same as thatshown in FIG. 38.

Configuration of Coils and Magnetic Sheets

In the embodiments illustrated in FIGS. 35-44, the configuration ofcoils and the magnetic sheet can be replaced with that of coils andmagnetic sheet discussed above with reference to FIGS. 1-40. Forexample, a magnetic sheet shown in FIG. 17 can be used as the magneticsheet shown in FIG. 38 or the magnetic sheet shown in FIG. 19.

Additional Embodiments

Embodiments shown in FIGS. 32-34 provides following features. Oneembodiment provides a smartphone antenna module for use in a smartphonecomprising:

-   -   a winding antenna comprising a winding of at least one wire with        an inner terminal and an outer terminal, the inner terminal        being located in an inner portion of the winding and the outer        terminal being located in an outer portion of the winding;    -   a flexible PCB (printed circuit board) comprising a thin        flexible body comprising a printed antenna portion, a bridge        portion and a connector portion;    -   the printed antenna portion comprising a printed antenna in the        flexible PCB;    -   a first conductive line formed in the flexible PCB and extending        between a first end and a second end, the first end and at least        part of the first conductive line formed in the bridge portion;    -   the connector portion accommodating at least part of the        connection terminals for the printed antenna and the winding        antenna for connecting to a counterpart connection terminal of a        smartphone; and    -   the bridge portion extending across the winding such that the        bridge portion and a portion of the winding overlap when viewed        in a viewing direction perpendicular to a major surface of the        bridge portion and further such that the first end of the        conductive line reaches the inner portion of the winding for        electrical connection with the inner terminal of the winding        antenna, the major surface being the most wide surface of the        bridge portion,    -   wherein a thickness of the bridge portion in the viewing        direction including the first conductive line integrated therein        is smaller than a thickness of the at least one wire in the        viewing direction.

In the smartphone antenna module of proceeding embodiment, the printedantenna portion including the printed antenna is at least in partthicker than the bridge portion including the first conductive line. Inthe smartphone antenna module of proceeding embodiments, the thicknessof the bridge portion at any point thereof is smaller than a thicknessof the printed antenna portion in the viewing direction. In thesmartphone antenna module of any one of the preceding embodiments, theprinted antenna and the winding antenna are arranged generally side byside such that the printed antenna and the winding antenna do notoverlap when viewed in the viewing direction. In the smartphone antennamodule of any one of the preceding embodiments, the antenna modulefurther comprises a second conductive line extending in the bridgeportion and comprising a third end and a fourth end, wherein the thirdend is connected to the outer portion of the winding for electricalconnection with the outer terminal of the winding antenna. In theantenna module shown in FIGS. 32-34, there is no electric connectionbetween the winding antenna and the coil antenna in the flexible PCB.

In the smartphone antenna module of any one of the precedingembodiments, each of the first and second conductive lines has athickness substantially smaller than its width (e.g., width at least 3times thickness). In the smartphone antenna module of any one of thepreceding embodiments, one of the first and second conductive lines hasa thickness substantially smaller than its width. In the smartphoneantenna module of any one of the preceding embodiments, the flexible PCBand the winding antenna are arranged generally side by side such thatthe printed antenna portion and the winding antenna do not overlap whenviewed in the viewing direction.

In the smartphone antenna module of any one of the precedingembodiments, the printed antenna and the winding antenna areelectrically decoupled within the smartphone antenna module. In thesmartphone antenna module of any one of the preceding embodiments, thesecond end is formed in the connector portion. In the smartphone antennamodule of any one of the preceding embodiments, the antenna modulefurther comprises a second conductive line formed in the flexible PCBextending between a third end and a fourth end. In the smartphoneantenna module of any one of the preceding embodiments, the third end isformed in the bridge portion, and the fourth end is formed in theconnector portion.

In the smartphone antenna module of any one of the precedingembodiments, the connector portion is referred to as a first connectorportion, the antenna module further comprises a second connectorportion, wherein the third end is formed in the second connectorportion, and the fourth end is formed in the first connector portion. Inthe smartphone antenna module of any one of the preceding embodiments,the connector portion is referred to as a first connector portion,wherein the antenna module further comprises a second connector portionand a third connector portion, wherein the third end is formed in thesecond connector portion, and the fourth end is formed in the thirdconnector portion. In the smartphone antenna module of any one of thepreceding embodiments, each of the first, second, third and fourth endscomprises a contact terminal pad.

In the smartphone antenna module of any one of the precedingembodiments, the contact terminal pads of the first and third ends facein a first direction wherein the contact terminal pads of the second andfourth ends face in a second direction opposite to the first direction.In the smartphone antenna module of any one of the precedingembodiments, the contact terminal pads of the first, second, third andfourth ends face in the same direction. In the smartphone antenna moduleof any one of the preceding embodiments, the connection terminals forthe winding antenna comprise the second end of the first conductive lineand the fourth end of the second conductive line.

In the smartphone antenna module of any one of the precedingembodiments, the printed antenna comprises a coil of a printed wire. Inthe smartphone antenna module of any one of the preceding embodiments,each of the first and second ends comprises a contact terminal pad. Inthe smartphone antenna module of any one of the preceding embodiments,the connection terminals for the printed antenna comprise first andsecond connection terminals connected to first and second ends of theprinted wire, respectively, wherein each of the first and secondconnection terminals comprises a contact terminal pad, wherein thecontact terminal pads of the first and second connection terminals andthe contact terminal pads of the first end of the first conductive lineface the same direction.

In the smartphone antenna module of any one of the precedingembodiments, the printed antenna comprises a coil of a printed wire,wherein the flexible PCB comprises a hole surrounded by the coil of theprinted wire. In the smartphone antenna module of any one of thepreceding embodiments, the coil of the printed wire comprises 2-7 turns,in one embodiment, 3-5 turns. In the smartphone antenna module of anyone of the preceding embodiments, a thickness of the printed antennaportion including the printed antenna is about 100-140 μm, in oneembodiment, about 120 μm, wherein a thickness of the bridge portionincluding the first conductive line is about 40-80 μm, in oneembodiment, about 60 μm. In the smartphone antenna module of any one ofthe preceding embodiments, the module further comprises a magneticmaterial plate attached to the flexible PCB. In the smartphone antennamodule of any one of the preceding embodiments, the magnetic materialplate comprises a ferrite plate which comprises a hole aligned with thehole of the flexible PCB.

In the smartphone antenna module of any one of the precedingembodiments, the winding antenna comprises a coil of aninsulation-coated wire. In the smartphone antenna module of any one ofthe preceding embodiments, the at least one wire comprises anenamel-coated wire, wherein the winding has a single layer of theenamel-coated wire such that the layer of the coil of the coated wirehas a thickness substantially same as the diameter of coated wire. Inthe smartphone antenna module of any one of the preceding embodiments,the enamel-coated wire has a thickness about 100-140, in one embodiment,120 μm. In the smartphone antenna module of any one of the precedingembodiments, the at least one wire comprise two or more wires, each ofwhich comprises the inner terminal and the outer terminal, wherein theinner terminals of the two or more wires are attached to the contactterminal pad of the first end of the first conductive line and the outerterminals of the two or more wires are attached to the contact terminalpad of the third end of the second conductive line such that the two ormore wires are electrically connected to each other in parallel. In thesmartphone antenna module of any one of the preceding embodiments, theinner end of the wire is welded to the contact terminal pad of the firstend of the first conductive line. In the smartphone antenna module ofany one of the preceding embodiments, the outer end of the wire iswelded to the contact terminal pad of the third end of the secondconductive line. In the smartphone antenna module of any one of thepreceding embodiments, each of the two or more wires has about 16-20turns, in one embodiment, about 18 turns.

In the smartphone antenna module of any one of the precedingembodiments, the number of two or more wires is 2 as shown in FIG. 16,wherein the inner ends of the two wires are attached to the contactterminal pad of the first conductive line, wherein the outer ends of thetwo wires are attached to the contact terminal pad of the secondconductive line, wherein the two wires are connected to each other inparallel. In the smartphone antenna module of any one of the precedingembodiments, the number of two or more wires is 3 or 4.

In the smartphone antenna module of any one of the precedingembodiments, the winding antenna does not comprise a portion of the wirewhich crosses the winding when viewed in the direction. In thesmartphone antenna module of any one of the preceding embodiments, thewinding antenna comprises an inner hole, wherein the smartphone antennamodule comprises a magnetic material sheet extending through the innerhole.

In the smartphone antenna module of any one of the precedingembodiments, the magnetic material sheet comprises a neck extendingthrough the inner hole and surrounded by the winding and a bodyconnected to the neck and extending from the neck and away from theflexible PCB. In the smartphone antenna module of any one of thepreceding embodiments, the magnetic material sheet is flat and thewinding antenna is stepped for allowing the magnetic material sheet toextend through the inner hole without substantial deformation of themagnetic material sheet. In the smartphone antenna module of theforegoing embodiment, the printed antenna is for near fieldcommunication (NFC), wherein the winding antenna is for magnetic securetransmission (MST). In the smartphone antenna module of any one of thepreceding embodiments, the printed antenna is configured to emit signalshaving about 13.56 MHz, and the winding antenna is configured to emitsignals having about 85-100 KHz.

Other embodiments provide a smartphone comprising:

-   -   a display disposed at the front side of the smartphone;    -   a housing comprising a rear cover with a camera hole;    -   the smartphone antenna module housed in the housing;    -   a camera module comprising a lens aligned with the camera hole;    -   the smartphone antenna module of any one of the preceding        embodiments; and    -   a smartphone circuit module housed in the housing and comprising        a connector portion which comprises terminals for electrically        connecting with at least one terminal of the smartphone antenna        module,    -   wherein the smartphone antenna module is arranged within the        housing such that the printed antenna portion of the smartphone        antenna module surrounds the camera module when viewing in a        direction perpendicular to the rear cover.

In the smartphone of proceeding embodiment, the rear cover comprises ametal plate and a plastic plate arranged in order along a longitudinaldirection of the rear cover, wherein the metal plate is substantiallylonger than the plastic portion in the longitudinal direction, whereinthe metal plate overlaps the flexible PCB and the winding antenna whenviewed in the viewing direction. In the smartphone of any one of thepreceding embodiments, the smartphone further comprises a magneticmaterial sheet comprising a main body and an insertion portion, whereinthe magnetic material sheet is arranged with the smartphone antennamodule such that the insertion portion is inserted into a centralopening of the winding antenna and the main body extends in a directionaway from the flexible PCB, wherein the metal plate overlaps theflexible PCB, winding antenna and the magnetic material sheet.

In the smartphone of any one of the preceding embodiments, the metalplate comprises an edge contacting, overlapping op neighboring theplastic plate, wherein the main body of the magnetic material sheetextends to or near the edge of the metal plate. In the smartphone of anyone of the preceding embodiments, the metal plate comprises an edgecontacting, overlapping op neighboring the plastic plate, wherein themain body of the magnetic material sheet extends to the plastic plate.In the smartphone of any one of the preceding embodiments, the metalplate extends at least three quarter the length of the rear cover in thelongitudinal direction of the smartphone.

In the smartphone of any one of the preceding embodiments, the flexiblePCB is disposed between the metal plate and the ferrite plate. In thesmartphone of any one of the preceding embodiments, the magneticmaterial sheet is substantially parallel to the rear surface of the rearcover. In the smartphone of any one of the preceding embodiments, themetal portion comprises a non-magnetic metal which is electricallyconductive. In the smartphone of any one of the preceding embodiments,the metal portion is made of aluminum.

In the smartphone of any one of the preceding embodiments, thesmartphone further comprises a plastic sheet disposed between thesmartphone antenna module and the rear cover. In the smartphone of anyone of the preceding embodiments, the smartphone further compriseanother plastic sheet disposed between the smartphone antenna module andthe smartphone circuit.

In embodiments, referring to FIGS. 32-34, when the winding antenna isassembled in a smartphone, the winding antenna can be used forwirelessly charging a battery in the smartphone. The smartphone has acontroller to control a charging circuit in the smartphone to operatethe winding antenna as a transformer coil for wirelessly charging abattery when the smartphone is placed close to a wireless charger. Inone embodiment, the entire portion of the magnetic sheet may be placedunder the winding antenna coil.

One or more features of each of the embodiments discussed above may bereplaced by one or more features included in the other embodimentsdiscussed above. For example, the magnetic sheet 300 of the embodimentshown in FIG. 3 can be replaced with the magnetic sheet 1300 of theembodiment shown in FIG. 19. Further, one or more features of oneembodiment discussed above may be added to the other embodiments. Forexample, the fourth coil 1210 of the embodiment shown in FIG. 22 can beadded to the flexible PCB of the embodiment shown FIG. 6 such that thefourth coil overlaps the first coil when viewed in the viewing directionand is connected to the first coil in series. In a further example, theconductive line segments 1280 and 1282 shown in FIGS. 22 and 23A and 23Bcan be added to all the other embodiments.

In embodiments, the antenna module illustrated in FIGS. 1-49 may furtherinclude a protective or covering sheet placed over and attached to theassembly of the flexible PCB and magnetic sheet. Further, forfacilitating to assembling the antenna module in the smartphone theantenna module further includes a step-compensation sheet placed overand attached to the assembly of the flexible PCB and magnetic sheet forreducing or minimizing steps that may be resulted from the assembly ofthe flexible PCB and the magnetic sheet having different sizes andshapes. This step-compensation sheet may be tailor-made or customized tofit a space required by the assembly of the flexible PCB and themagnetic sheet. These can be made of a plastic resin material.

In the foregoing discussions, the antenna module according toembodiments are used as a smartphone antenna module that is to beinstalled in the smartphone. In the foregoing discussions, thesmartphone may include any mobile device that can provide voicecommunication and data communication through wireless networks. Inembodiments, the antenna modules discussed in the above can be used in alaptop computer, a slate computer, a personal digital assistant, aportable multimedia player, a navigation device, a wearable device, etc.

Although embodiments of the invention have been described above, thoseskilled in the art may understand that configurations of the variousembodiments described above may be changed without departing from thespirit of the invention. It will be also understood that the changesfall within the scope of the invention.

What is claimed is:
 1. A smartphone antenna module comprising: aflexible PCB comprising a sheet-like body with a first major surface anda second major surface facing away from the first major surface; theflexible PCB further comprising a through-hole formed through thesheet-like body, wherein the flexible PCB comprises a first PCB section,the through-hole and a second PCB section arranged along an axis suchthat the axis passes the first PCB section, the through-hole and thesecond PCB section in order; the flexible PCB further comprising a firstcoil, a second coil and a third coil formed in the sheet-like bodybetween the first and second major surfaces; the first coil comprising afirst coil segment located in the first PCB section and a second coilsegment located in the second PCB section; the second coil comprising afirst coil segment located in the first PCB section and a second coilsegment located in the second PCB section; the third coil located in thesecond PCB section; the second coil surrounding the first coil, thethrough hole and at least a portion of the third coil; and a magneticsheet comprising a head portion, a base portion and a neck portionbetween and interconnecting the head and base portions, wherein noelectric connection is formed between any two coils of the first, secondand third coils in the flexible PCB, wherein the magnetic sheet isengaged with the flexible PCB: such that the head portion is located onthe side of the first major surface and overlaps the first coil segmentof the first coil, in which the head portion overlaps at least one lineof the first coil segment of the first coil while the head portion doesnot overlap any line of the first coil segment of the second coil, suchthat the neck portion passes through and overlaps the through-hole, andsuch that the base portion is located on the side of the second majorsurface and overlaps the third coil, the second coil segment of thefirst coil and the second coil segment of the second coil, in which thebase portion overlaps each line of the second coil segment of the firstcoil, each line of the second coil segment of the second coil and eachline of the third coil and the entire portion of the third coil, whereinthe magnetic sheet overlaps each line of the second coil segment of thesecond coil whereas the magnetic sheet does not overlap any line of thefirst coil segment of the second coil.
 2. The smartphone antenna moduleof claim 1, wherein the third coil is located between the second segmentof the first coil and the second segment of the second coil, wherein thesecond coil surrounds the entire third coil.
 3. The smartphone antennamodule of claim 1, wherein the second coil segment of the second coilcomprises a plurality of lines generally perpendicular to the axis,wherein the plurality of lines comprises a first line and a second linelocated inside the first line, wherein the second line crosses the thirdcoil when viewed in a thickness direction of the flexible PCB whereas afirst line does not cross the third coil such that the entire portion ofthe third coil is located between the second line and the second segmentof the first coil.
 4. The smartphone antenna module of claim 1, whereinthe second coil comprises two or more turns that comprises a first turnand a second turn, wherein the first turn surrounds entire portion ofthe third coil whereas the second turn surrounds a portion of the thirdcoil and comprises a line crossing the third coil when viewed in athickness direction of the flexible PCB.
 5. The smartphone antennamodule of claim 1, wherein each of the first, second and third coilscomprises a printed wire that is coiled to form one or more turns in aspiral shape when viewed in a thickness direction of the flexible PCB.6. The smartphone antenna module of claim 5, wherein the printed wirecomprises a first wire segment and a second wire segment formed indifferent layers of the flexible PCB and connected through a connectionvia.
 7. The smartphone antenna module of claim 1, wherein each line ofthe second coil segment of the first coil comprises a linear extensionalong a direction perpendicular to the axis, wherein the base portionoverlaps the entire portion of the linear extension of the first coilalong the direction, wherein each line of the second coil segment of thesecond coil comprises a linear extension along a direction perpendicularto the axis, wherein the base portion overlaps the entire portion of thelinear extension of the second coil along the direction.
 8. Thesmartphone antenna module of claim 1, wherein each line of the firstcoil segment of the first coil comprises a linear extension along adirection perpendicular to the axis, wherein the head portion overlapsthe at least one line of the first coil segment such that only a centralportion of the linear extension of the at least one line overlaps thehead portion with non-overlapped portions at both ends of the centralportion.
 9. The smartphone antenna module of claim 1, wherein themagnetic sheet includes a portion extending from the base portion beyondan edge of the flexible PCB that overlaps with the second PCB section.10. The smartphone antenna module of claim 1, wherein the first coilantenna comprises third and fourth coil segments that do not overlap themagnetic sheet at all, wherein the first, third, second and fourth coilsegments of the first coil are arranged in order surrounding the throughhole.
 11. The smartphone antenna module of claim 1, wherein the secondcoil antenna comprises third and fourth coil segments that do notoverlap the magnetic sheet at all, wherein the first, third, second andfourth coil segments of the second coil are arranged in ordersurrounding the through hole.
 12. The smartphone antenna module of claim1, wherein the head portion has a first width for passing through thethrough hole without bending thereof whereas the base portion has asecond width for not passing through the through hole without bendingthereof.
 13. The smartphone antenna module of claim 1, wherein the baseportion has a width greater than that of the neck portion, and the headportion has a width equal to or smaller than that of the neck portion.14. The smartphone antenna module of claim 1, wherein the neck portionhas a width smaller than those of the head portion and the base portion.15. The smartphone antenna module of claim 1, wherein the through-holehas a maximum linear length of an opening thereof, wherein the headportion has a first width smaller than the maximum linear length whereasthe base portion has a second width larger than the maximum linearlength.
 16. The smartphone antenna module of claim 1, wherein each ofthe first, second and third coils comprises an inner terminal and anouter terminal, wherein the flexible PCB further comprises a PCBconnector for electrically connecting each coil to a counterpartconnector of a smartphone, wherein the PCB connector is electricallyconnected to the inner terminal and the outer terminal.
 17. Thesmartphone antenna module of claim 1, wherein the flexible PCB furthercomprises a connection line interconnecting the inner terminal of thefirst coil antenna and the PCB connector, wherein the connection linecrosses over the first coil antenna and the second coil antenna withoutelectric connection with the second coil in the flexible PCB.
 18. Thesmartphone antenna module of claim 1, wherein the flexible PCB furthercomprises a fourth coil formed in a layer different from that of thefirst coil, wherein the fourth coil surrounds the through-hole, whereinthe fourth coil is coiled in a rotational direction opposite that of thefirst coil when viewed in a thickness direction of the flexible PCB,wherein the first coil and the fourth coil are electrically connected inseries.
 19. The smartphone antenna module of claim 1, wherein theflexible PCB further comprises a fourth coil formed in a layer differentfrom that of the first coil, wherein the fourth coil surrounds thethrough-hole, wherein the first and fourth coils are coiled in the samerotational direction when viewed in a thickness direction of theflexible PCB, wherein the first coil and the fourth coil areelectrically connected in parallel.
 20. The smartphone antenna module ofclaim 1, wherein the flexible PCB further comprises a fourth coil formedin a layer different from that of the first coil, wherein the fourthcoil surrounds the through-hole, wherein the fourth coil comprising afirst coil segment located in the first PCB section and a second coilsegment located in the second PCB section such that the first coilsegment of the fourth coil overlaps the head portion while the secondcoil segment of the fourth coil overlaps the base portion.
 21. Asmartphone comprising: a display module comprising a display surface;the smartphone antenna module of claim 1; and a rear wall facing awayfrom the display surface and made of a non-magnetic material, whereinthe magnetic sheet is arranged generally parallel to the rear wall. 22.The smartphone of claim 21, wherein at least part of the base portion isinterposed between the rear wall and the second PCB section whereas atleast part of the first PCB section is interposed between the rear walland the head portion.
 23. The smartphone of claim 21, wherein the firstcoil antenna is connected to a first smartphone circuit and configuredfor magnetic secure transmission (MST) using a frequency range of 85-100KHz, wherein the second coil antenna is connected to a second smartphonecircuit and configured for near field communication (NFC) using 13.56MHz, wherein the third coil antenna is connected to a third smartphonecircuit and configured for wireless charging of the smartphone.